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I was watching a very recent TV show, the FBI agent told the police that there is no way for anybody to block a live stream of a pedophile torturing a kid nor to trace it. Even when it's being broadcasted from within the same country.

What am I missing here? I can think of lots of ways to block and the website and trace the owner of the domain. Was it just fiction?

  • Although not related to an answer, was the show "Criminal Minds"? – hd. Nov 18 '14 at 11:45
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    No, it's Law & Order: Special Victims Unit". – Ulkoma Nov 18 '14 at 12:24
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"Can't be blocked" is impossible. Even if you don't know the location of the source (say, they're using a censorship-resistant system such as a Tor hidden service), you can still perform a denial-of-service attack, though doing so would have substantial collateral damage (a successful DoS on a Tor hidden service will likely render the entire Tor network unusable).

If you can find the source of the stream, there are many ways of blocking it, of varying degrees of legality, ranging from sending a takedown notice to the relevant ISP, to BGP hijacking.

"Can't be traced" is a different matter. Censorship-resistant networks such as Tor or Freenet are designed to be difficult to trace: finding a Tor hidden service might require the cooperation of eight different countries' police forces (six for the Tor nodes passing data along, plus the investigating country and the one the server is in). Freenet is even harder: unless you're watching as someone uploads a file to the network, it's impossible to tell the original source of that file.

In the scenario described in the question, the use of Tor is unlikely: Tor's latency is too high and the bandwidth too uncertain for streaming video. Additionally, there's no way to have "partial" knowledge of someone's location: it's either all or nothing. Freenet can't have been used, since it's essentially a distributed file store rather than a network of servers; streaming video over Freenet is impossible.

  • Why not insert each minute of video to Freenet as a CHK and then make a freesite with a list of all CHKs so far? Or is insertion too slow for anything remotely approaching live? – Damian Yerrick Nov 18 '14 at 4:03
  • @tepples, things may have changed in the past five years or so, but back when I was actively using Freenet, my usual procedure was to start a bunch of actions (page loads, downloads, etc.) and check back after 15 minutes or so for the results. – Mark Nov 18 '14 at 6:32
  • Upvoted for mentioning the problems with the latency Tor has. – Nzall Nov 18 '14 at 8:16
  • For what it is worth, I have personally witnessed good quality video+audio streamed live over Tor and projected onto a screen at the front of an auditorium full of very impressed geeks. That being said, a LOT of preparation and cooperation went into making that happen, and it was announced at the beginning that the audience should not be too disappointed if the connection dropped off in the middle. But, it didn't. :) – daveloyall Jan 7 '15 at 20:49
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As far as I can tell, you’d need to define where it would be “Live Streaming” from. For example, if someone used darknet (Onion/TOR) to stream, it would be very difficult since there are a lot of randomized layers. No one would be able to block a live stream since it would come from various sources (nodes). There could be no mechanism to have ISPs block their clients from viewing it either, as they’d have to block TOR protocols, and it does nothing if someone uses even more proxies to bypass the blocks.

There would be a mechanism to determine who had watched it, based on checksums, length of the stream, and other tidbits investigators could piece together, however that too becomes a touchy subject since they’d literally have to have all ISPs do some form of flow (netflow/jflow) and calculations.

Short answer is, they would be hard pressed to stop it without breaking laws, and violating privacy while doing so.

  • It wouldn't even be possible to tell who watched it if the stream is encrypted. Multicast streaming doesn't work over the open internet and I don't think TOR has support for it either, so you would need to establish a unique connection for each viewer and the encryption would make it impossible to checksum to identify content. You could possibly length match, but some basic padding on the stream would destroy that. – AJ Henderson Nov 17 '14 at 19:13
  • Tor connections are untraceable not because there are a lot of randomized layers, but because it is based on onion routing where a layer only knows about the previous and next one. Typically a client uses a three layer path, and in case of hidden services, the client and server rendezvous after three hops each for a total of six hops. – ntoskrnl Nov 17 '14 at 22:17
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    Think about it like this: Of course you can block it, for example by turning off all electricity in your country, or shutdown all ISPs. The question is how much has to go down in collateral by blocking it - and the answer most likely is: too much for any practical case. Especially if some people use a VPN-Proxy to another country, you'd have to shut all of them down, too including a lot of business connections – Falco Nov 18 '14 at 10:05
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For police, requests like this are made to the ISP (which would be easy to ascertain), or the streaming or hosting service (also easy).

The problem is the timeframe. It would take time to coordinate with the ISP or service. It is going to be 'impossible' to turn off a website within an hour, for instance.

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