Are there any services/agencies running a large number of nodes so that they can guess the IP address of a transaction's origin?
I guess they would need to run tens of thousands of nodes. However it'll be useful in tracing stolen coins. Surely there must be some.
I have seen talks and papers claiming to do so but not found any such service.
I see this as a non-issue. By using Tor the IP address of the originator is sufficiently obfuscated.
See my two other posts for some discussion and related resources:
When you (a node) receive a transaction, you are not sure if you are receiving it from a node forwarding a transaction to other nodes on the network or if you are the first node in the web to receive the transaction to your mempool.
There are services which are engaged in meta data analysis that are likely revealing a surprising amount of information from studying mempool generation and the block chain. Exactly what they are discovering is still very obscure. At least one study by Chainanalysis has determined about 4 million coins are off the market indefinitely. (Source: http://fortune.com/2017/11/25/lost-bitcoins/ ) This service offers Blockchain analysis to exchanges, government agencies and financial institutions, publishes some findings from time to time for publicity, but is otherwise inaccessible to the individual as the amount of resources they invest into analysis requires significant compensation, though I suspect if they ever discover a use for their data that could be marketed to the masses they would likely develop a service for it.
The fact that there is no one out there marketing a way to track bad actors, either in service to the government or public, indicates that the technology does not yet exist, or the laws don't provide a means by which such analysis could be put to productive use. Some people still publish addresses and stories of bad actors to forums for community awareness, essentially providing an ad hock address blacklist. This is so easily circumnavigated by services such bitcoin gambling sites and address washing services that I don't believe anyone is curating a 'master blacklist' of the reports. Currently blockchain analysis is focused on detecting KYC/AML violators, money launderers, and in general providing some kind of evidence that a company is performing their due diligence in preventing bad actors from using their services, which here means a token effort and expense that reduces their liability in the case of a damaging law suit.
