An Internet provider can determine from which subscriber devices using a torrent or p2p they distribute this or that file knowing only the file name?

Question

Computer networks

Let's suppose that the Internet provider receives such a request from the police (Provide information about the subscriber device to which this IP address was allocated on November 9, 2014 AND INFORMATION ABOUT ALL subscriber devices from which AT THIS TIME the file name is "14-year-old masturbation xxx)
The provider will be able to determine from which subscriber devices a file with such names is being distributed to the Internet (we are NOT talking about the provider's local network)?

Answer 1

It all depends on the qualifications of the provider's employees and the level of traffic analysis systems. Theoretically, this is possible. Having a torrent file and the file itself - you can catch packets containing parts of the torrent and the file itself - powerful computers are required for real-time analysis. Knowing the direction of the packets, you can determine the direction of data transfer. Also, the provider will know the actual connection address - even if it differs from the address in the contract. That is, even if you connect at the entrance of another house, the provider will know which one. The only legal question remains - when intercepting traffic containing all parts of a file - will this file be required on the computer? And if the contract with the provider is concluded for nominees (homeless people),
In general, if you downloaded and gave the file, then the evil uncles from the "K" department may well come to you. Everything can be done if desired. The provider may cache your torrent files downloaded via insecure channels. But the provider can only identify its subscribers. The maximum that will be known about other subscribers is their IP address.

Answer 2

The provider is deeply violet from which specific device the distribution is being made, he will not bother with this, he will simply give the subscriber's data to the request of the authorities, and then there is the problem of the police.