the invention is described in detail below with reference to the figures , wherein like elements are referenced with like numerals throughout . referring to fig2 , an anti - theft / retrieval system 200 is illustrated . the system 200 includes a reader 202 coupled to a corridor 204 through which a person 206 may walk . as shown in fig2 , the person 206 is carrying a device 208 having a transmitter 210 embedded therein . the transmitter 210 transmits information related to the device 208 to the reader 202 when the transmitter 210 is within a defined distance from the reader 202 . in this way the reader 202 detects the presence of the device 208 and is able to identify it . in one embodiment , the corridor 204 may be a metal detector such as those typically located in or near an airport terminal . alternatively , the corridor 204 may be replaced by an x - ray machine , such as those which are typically located next to a metal detector in an airport , which includes a conveyor belt for transporting items placed thereon under an x - ray scanner . by placing the rfid reader 202 near the metal detector and / or the x - ray machine of an airport checkpoint , the invention provides a security measure against persons trying to board a plane with lost or stolen property . alternatively , or as an additional security measure , a reader 202 may be positioned near a baggage check - in point such that all baggage being loaded into a plane may be screened for lost or stolen devices . therefore , by placing readers 202 at strategic checkpoints , within an airport , for example , a radio frequency security net / retrieval system is established which can identify lost / stolen items and assist security personnel stationed near each checkpoint in retrieving the lost / stolen devices . as used herein , the term “ checkpoint ” refers to any location or point in which people and / or items must pass in order to move on to another location or point . in the scenario described above , it may be preferable to utilize a transmitter 210 , and / or reader 202 with a short transmission / reception range , e . g ., six feet , so as to not read transmitters that are far away from the reader 202 . since it is an object of the invention to identify a particular item which has been reported to be lost or stolen , it is counter - productive to receive information from multiple transmitters located in different areas . in such a scenario , one could not be sure which transmitter was transmitting information indicating the presence of a lost or stolen item . in one embodiment , the transmitter 210 is a passive rfid tag . coupled to the reader 202 is a computer 212 which receives information from the reader 202 and compares the information to a list of lost and / or stolen devices , stored in a database 214 coupled to the computer 212 . upon comparing the information received from the transmitter 210 to the list of lost and / or stolen devices , the computer 212 determines if there is a match . if there is a match , the computer 212 generates an appropriate alarm signal to notify personnel stationed near the location of the reader 202 and corridor 204 of the status of the device 208 so that appropriate action can be taken . as used herein , the term “ list ” refers to any format in which data , or information may be stored so as to be retrievable for purposes of review and / or analysis . in one embodiment , the transmitter 210 may be a standard radio frequency identification ( rfid ) tag which is well - known in the industry . in another embodiment , the transmitter 210 is a microstamp ® remote intelligent communications ( ric ) device , manufactured by micron communications , inc . microstamp ® is a registered trademark for a family of ric devices that use active and passive transmitters . however , ric devices differ from traditional rfid devices in that ric devices typically have a battery , a microprocessor , a high - frequency radio , more memory and longer range capability when compared to standard rfid devices . the microstamp ® ric device contains a microstamp engine ™ integrated circuit ( ic ), which combines a direct sequence spread spectrum ( dsss ) microwave frequency radio , a microcontroller , and a low power static random access memory ( sram ) into a single chip . the microstamp engine ic , when coupled with an antenna and a battery , forms the microstamp ric device . because the ic combines hundreds of thousands of components on one small chip , the microstamp ric device may be assembled , with a small battery , into very small packages , making it ideal for applications in small handheld , or portable , electronic devices . although ric devices are typically more advanced than standard rfid tags , as used herein , the term “ radio frequency identification ,” or “ rfid tag ”, or “ rfid device ”, and any combination or conjugation thereof , refers to both standard rfid devices and ric devices as described above , as well as any radio frequency transmission device , capable of transmitting data for identification purposes to a receiver . in one embodiment , the reader 202 is a microstamp ® 4000 rf interrogator , manufactured by micron communications , inc . the function of this interrogator 202 is twofold : 1 ) it receives commands and data from the computer 212 and sends data packets to the remote intelligent communications ( ric ) unit 210 , and 2 ) it receives reply packets from the ric unit 210 and passes the reply back to the computer 212 . when the interrogator 202 receives a command from the computer 212 , the interrogator 202 either executes the command internally , or transmits the command to the ric unit 210 . the ric unit 210 then executes the command , but may or may not reply , depending on the command &# 39 ; s specific function . when the ric unit 210 replies , the interrogator 202 passes the reply back to the computer 212 . this communication protocol between the ric unit 210 , the interrogator 202 and the computer 212 is well - known in the art . in one embodiment , the computer 212 is directly connected to the reader 202 by the communications link 216 , which may be any type of electrical cable having a parallel or serial port connector for interfacing with the external ports of the computer 212 ., such as an enhanced parallel port ( epp ), rs - 232 , rs - 422 or rs - 485 communications line , for example . as mentioned above , the communications link 216 may be any type of well - known communications links , or medium , used for transmitting data from one device to another . in one embodiment , the computer 212 may be located near the reader 202 such that security personnel can view a display screen ( not shown ) of the computer 212 as people pass through the corridor 204 to verify that each person passing through is not carrying an item which has been reported to be lost or stolen . if a person passing through the corridor 204 is carrying a lost or stolen item , the computer 212 should identify the item and , thereafter notify security personnel by displaying a message on its display screen or providing a visual and / or auditory alarm signal . alternatively , the computer 212 may be a local computer 212 , that is not located near any one reader 202 but , instead , has many readers 202 coupled to it , each reader monitoring a different checkpoint . in this scenario , each reader 202 at each checkpoint requires a means for alerting security personnel stationed at each of the checkpoints . this function can be performed in a number of different ways . for example , an operator monitoring the local computer 212 can call , via telephone , intercom , radio , etc ., security personnel located at a particular checkpoint with instructions . alternatively , the local computer 212 may send an alarm signal to a device located near the particular checkpoint which can provide a visual and / or auditory alarm signal to security personnel stationed at the checkpoint . as shown in fig2 , the anti - theft / retrieval system 200 may further include a central database 218 which is coupled to the local computer 212 by a communications link 220 . the communications link 220 may be any one of various well - known communications links or mediums which can be used to transmit data from one device to another . as described in further detail below , a primary function of the central database 218 is to store a master list of lost or stolen devices and periodically update a local list of lost or stolen devices contained within the database 214 of the local computer 212 . referring to fig3 , the central database 218 ( fig2 ) may be a computer server 218 which is connected via a computer network 300 , to many local computers 212 . each local computer 212 may in turn be interfaced with one or more readers 202 , each reader 202 being responsible for monitoring a specified area , or checkpoint , as described above . any well - known communications protocol , such as the ethernet communications protocol , may be used to transmit data between each of the multiple local computers 212 and the central server 218 . the computer network 300 may be a local area network ( lan ), a wide area network ( wan ), or alternatively , a part of the global computer information network , otherwise known as the internet . in order to police for lost or stolen items , a system must be established to report and record lost and stolen items in an efficient and timely manner . for example , after an owner of an item has reported the item to be stolen , its serial number , or other identifying information , should be promptly stored in the central database 218 and provided to each of the local computers 212 to enable them to monitor for the item within a relatively short time after it has been reported to be lost or stolen . therefore , in one embodiment , the database 214 within the computer 212 is periodically updated with the latest list of lost or stolen goods from the central database 218 . the frequency of these updates can be responsive to addition or deletion of an item from the master list stored in the central database 218 , or alternatively , the update can occur at predetermined time intervals . for example , when an owner of a laptop computer discovers that his or her laptop is lost or stolen , the owner can report the missing item to a manufacturer , dealer , or other authorized agent , who can then add the lost / stolen computer to the list of lost / stolen items in the central database 218 . the authorized agent may then input the lost / stolen computer &# 39 ; s serial number into the central database 218 . this serial number is the information , or at least part of the information , which is transmitted by the transmitter 210 ( fig2 ) which is contained in the laptop computer . additional information transmitted by the transmitter 210 may be the name and address of the registered owner of the laptop computer , for example . when a person carrying the lost / stolen laptop computer attempts to pass through a checkpoint , represented by corridor 204 in fig2 , the reader 202 receives the serial number transmitted by the transmitter 210 and forwards this serial number to the computer 212 for comparison with the list of lost or stolen items . if there is a match , the computer 212 generates an alarm signal which is communicated to proper authorities . after a lost or stolen laptop computer has been retrieved , its serial number , or other identifying information should be removed from the master list of lost or stolen devices . when local lists are updated by the master list , the retrieved laptop computer will also be removed from all local lists of lost or stolen devices . for security reasons , the list of lost or stolen goods should only be accessible by authorized personnel . in one embodiment , to add or delete an item from the list of lost or stolen items which is stored in the central database 218 , a person must provide a password to verify and authenticate his or her identity . only after such a password is received and verified can that person obtain access to the central database 218 . it is also contemplated that the owner of the laptop computer will be able to personally call a “ hotline ” telephone number that allows the owner to add the serial number of his or her lost laptop computer to the master list of lost or stolen goods , after passing certain security measures , such as entering a registered password , for example . referring to fig4 , a perspective view of a portable computer 400 is illustrated . the computer 400 includes a transmitter 210 located within the housing of the computer 400 . as mentioned above , the transmitter 210 may be an rfid tag , which is well - known in the art , or a microstamp ric unit , manufactured by micron communications , inc . however , other types of transmitters which are compact in size and capable of transmitting information at desired frequencies and ranges may be utilized in accordance with the invention . the transmitter 210 should be permanently attached to an internal portion of the computer 400 so as to not be easily accessible . therefore , a thief would not be able to circumvent the security features provided by the transmitter 210 by simply removing the transmitter 210 . in one embodiment , the transmitter 210 is embedded in the housing of the computer 400 during its manufacture . since typical radio frequency devices are capable of transmitting and receiving data when encapsulated by plastic , or other similar materials , encapsulating the transmitter 210 within a portion of the housing of the computer 400 , will not significantly degrade the performance of the transmitter 210 . after the transmitter 210 is programmed with a serial number , or other identifying information , related to the computer 400 , the transmitter 210 can transmit this information . in one embodiment , this information may be programmed into the memory of the transmitter 210 by utilizing a designated reader 202 ( fig2 and 3 ) to transmit the information to the transmitter 210 and store the information in a memory of the transmitter 210 . in one embodiment , for security purposes , the designated reader 202 may be required to provide a password which allows it to write to the memory of the transmitter 210 , or alternatively , the information transmitted by the reader 202 may be encrypted such that only the transmitter 210 can read and store the information . such methods of programming rfid / ric transmitters are well - known in the art . however , any well - known method of programming the transmitter 210 may be utilized in accordance with the invention . once the identifying information has been stored in the memory of the transmitter 210 , it should be unalterable , except by authorized personnel and / or the registered owner of the item containing the transmitter 210 . any well - known method of ensuring the integrity of the information stored in the transmitter 210 , such as password protection and / or encryption schemes , may be utilized in accordance with the invention . as described above , the invention provides a method and system which utilizes radio frequency technology to identify lost or stolen goods that randomly come within range of a reader capable of receiving information transmitted by a radio frequency transmitter permanently fixed within the lost or stolen goods . after identifying an item which has been reported to be lost or stolen , the method and system notifies designated personnel , as necessary . the invention may be embodied in other specific forms without departing from its spirit or essential characteristics . the described embodiments are to be considered in all respects only as illustrative and not restrictive . the scope of the invention is , therefore , indicated by the appended claims , rather than by the foregoing description . all changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope .