I live in a metropolitan area of around 500,000 and there are close to 200 markers indicating an IP address that's advertising CP availability.

We have methods of rating each marker (e.g. how many CP files, how many are teen, child, nudity vs. intercourse, etc). Of those 200, there are a handful of the worst offenders that law enforcement will use resources to pursue, a group in the middle that have downloaded a large number where victims are 12-18, and then those who have just a few random files from the known list.

Does that help?

<markers indicating an IP address that's advertising CP availability.>

Sorry if this is a dumb question, but what does that mean? There are 200 servers with that stuff in your city? If you know their IP can't you get a warrant and shut them down? I find it strange that the police know about so many people doing this stuff but don't do anything about it but maybe that's not what you mean? It seems pretty cut and dry if someone is advertising illegal stuff.

Yes they can get a warrant, and they do, but there's honestly so much of it out there that there's only so many hours in a day for investigators to subpoena information, arrest someone, do forensics on their computer, prosecute the suspect, etc etc. Far less serious offense, but it's similar to how the RIAA/MPAA can only go after so many music/movie pirates out there.

How do you avoid prosecution? Being in possession of child pornography is a crime. If you personally identified these torrents, then you are essentially confessing.

There is an interesting story in "Three Felonies a Day" where an employer discovers child pornography on an employee's computer. They contact their attorney, and the lawyer deletes the offending contact to protect the company. He then alerts authorities to the employee. The attorney is eventual prosecuted for evidence tampering. It's an absurd Catch 22.

After re-reading: you avoid prosecution by not being a large enough offender, or by offending in a jurisdiction where law enforcement is not trained to catch you. Not all that different than avoiding prosecution as a recreational drug user when the cops are too busy going after bigger fish.

There's a lot of time and resources spent in between the time of identifying that an IP address is broadcasting CP to having all the information you need to bust down the right door and lock up the guy for a long time.

Taking your example of image analysis, companies in this space will build applications that - for instance - identify which images of the 10,000 on a bandit's computer are all the same kid. The software company would use sample images of clothed kids to demonstrate how it works, then only law enforcement would input confiscated CP images to do the analysis.

I meant how do you avoid prosecution when analyzing these images for the purpose of catching the people spreading them? There is no "fair use" for contraband. Therefore, it would be hard to build a company around technology for stopping child pornography.

Example of what private companies can do - http://www.huffingtonpost.com/2011/05/20/facebook-photodna-m...

That doesn't sound like a Catch 22, that sounds like someone interfering with evidence. The absurd thing is if the company or lawyer would be prosecuted for not deleting the evidence. I'd hope not, cause they didn't do anything wrong if their employee did the wrong thing.

I did/do not personally identify them. I describe that law enforcement has tools to do so, but limited resources (and difficulties with ISP cooperation) to go after all of them.

Where are you getting this data from?

Privileged law enforcement information. Sorry but I cannot say more.

Can I ask how one gets into that gig?

Professionally? Contact your Sheriff's Office and ask to speak with someone from their internet crimes or child crimes/exploitation unit. They're always looking for talented people in those areas.