1. A two stage method for logging a first user in to a mobile computing device being in a locked mode, said method comprising: (a) storing data associated with the first user and storing information that relates to a facial image of that first user, at a memory of the mobile computing device; (b) when the mobile computing device is in a locked mode: (b.1) receiving data inserted by a user who wishes to unlock the mobile computing device; (b.2) comparing the received data with the stored data associated with the first user and determining whether the received data matches the stored data associated with the first user; (b.3) if it has been determined that the received data matches the stored data associated with the first user, prompting an image capturing device associated with the mobile computing device to capture a facial image of the user who inserted the data received; (b.4) retrieving information that relates to a facial image of the user who inserted the received data and comparing that information with information that had been stored at the memory of the mobile computing device, wherein the latter information relates to the facial image of that first user; (c) if the retrieved information relating to a facial image of the user who inserted the received data matches the information relating to the facial image of the first user which has been stored at the memory of the mobile computing device, unlocking the mobile computing device, and wherein in case the image captured in step b.3 cannot be used for extracting enough information in order to carry out a matching process with the information relating to the facial image of the first user which has been stored at the memory of the mobile computing device, the method further comprises the steps of: (d.1) enabling limited access to resources of the mobile computing device; (d.2) triggering the image capturing device to capture another image and processing the newly captured image; and (d.3) if the newly captured image cannot be used for extracting enough information in order to carry out a matching process with the information relating to the facial image of the first user which had been stored at the memory of the mobile computing device, repeating steps d.2 and d.3 for up to a pre-defined number of times; and (d.4) if following that pre-defined number of times, no match has been found between the extracted information and the information relating to the facial image of the first user which had been stored at the memory of the mobile computing device, logging off the user who was granted with a limited access to the mobile computing device.