How do I investigate an address or transaction? 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?
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.