user4708: My non-profit organization received a donation for which no one contacted us to claim credit.  I am intrigued and would like to find out as much as I can about the donor using the blockchain.  What services / tools exist to do this?  Some ideas I have are:

Did he/she embed a text message in the transaction?
Can any information be gleaned from the web of transactions involving that address?


user4139: The simplest way to get information about the transaction is to use the Blockchain web site.  They have some easy-use-tools that can show you which transactions the funds came from, and the submitting IP address.  Use the URL http://blockchain.info/tx/transactionid.
For example: http://blockchain.info/tx/cc4ffa39d766fadfc6bd48a2144492e6e7b07c9b4046f7edbad3ec63869dd071
I don't think you'll get much information about the IP address, because addresses are not part of the transaction information.  A Bitcoin host only knows the address of the peer that relayed a transaction, which usually isn't the originating address.
You can trace what other transactions your donation came from, but putting a name to a bitcoin address can be difficult.  Your best bet might be to do a Google search for the address of some of the upstream transactions.  If someone used their well-known address for donating, then you might be able to find them.  But if the originating addresses were never put onto a web page by their owners, then you're out of luck.
If you are a government and the funds originated through one of the currency exchanges, you could use a warrant to get whatever information the exchange has on a transaction.  Given the state of privacy rights these days... well don't get me started.

4708: <p>My non-profit organization received a donation for which no one contacted us to claim credit.  I am intrigued and would like to find out as much as I can about the donor using the blockchain.  What services / tools exist to do this?  Some ideas I have are:</p>

<ul>
<li>Did he/she embed a text message in the transaction?</li>
<li>Can any information be gleaned from the web of transactions involving that address?</li>
</ul>
 4139: <p>The simplest way to get information about the transaction is to use the Blockchain web site.  They have some easy-use-tools that can show you which transactions the funds came from, and the submitting IP address.  Use the URL <a href="http://blockchain.info/tx/_transactionid_" rel="nofollow">http://blockchain.info/tx/<em>transactionid</em></a>.</p>

<p>For example: <a href="http://blockchain.info/tx/cc4ffa39d766fadfc6bd48a2144492e6e7b07c9b4046f7edbad3ec63869dd071" rel="nofollow">http://blockchain.info/tx/cc4ffa39d766fadfc6bd48a2144492e6e7b07c9b4046f7edbad3ec63869dd071</a></p>

<p>I don't think you'll get much information about the IP address, because addresses are not part of the transaction information.  A Bitcoin host only knows the address of the peer that relayed a transaction, which usually isn't the originating address.</p>

<p>You can trace what other transactions your donation came from, but putting a name to a bitcoin address can be difficult.  Your best bet might be to do a Google search for the address of some of the upstream transactions.  If someone used their well-known address for donating, then you might be able to find them.  But if the originating addresses were never put onto a web page by their owners, then you're out of luck.</p>

<p>If you are a government and the funds originated through one of the currency exchanges, you could use a warrant to get whatever information the exchange has on a transaction.  Given the state of privacy rights these days... well don't get me started.</p>
