Child porn is strict liability (meaning, there's no requirement to show you did anything on purpose). The law generally doesn't require that you be aware of the legality of what you're doing ("ignorance of the law is no excuse").
Now, it's easy for me to believe that if you can show affirmatively that you received child porn by accident, for example through the unknown-to-you malicious actions of others, the judge might let you off, but that's not actually encoded in the law; the federal agents you mention have an accurate view of things.
Can you point out a case where someone knew they were in possession of or receiving child porn, but got off because they were under the impression it was legal?
Now, it's easy for me to believe that if you can show affirmatively that you received child porn by accident, for example through the unknown-to-you malicious actions of others, the judge might let you off, but that's not actually encoded in the law; the federal agents you mention have an accurate view of things.
If you can show affirmatively that you received child porn by accident, the judge will let you off, because there wasn't any intent to possess child porn. Moreover, the prosecution will go after the person who sent the porn to you, and will likely recommend a good civil attorney for your lawsuit against that person.
Kind of like destroying someone's reputation via sybil attacks, on an app like lulu or yelp or whatever. The NSA had slides on how fake victims could write blogs about being raped or mistreated or whatever.
The mail service has a remarkable ability to track mail packages, even those not sent by certified or registered mail. Additionally, police stations log all calls received--there's no such thing as an anonymous call. The use of a pay phone, prepaid cell phone, or online burner number is a huge red flag--it supports the recipient's defense that someone is attempting to ruin their reputation. Plus, almost all child pornography cases are coordinated with a special DOJ task force, due to the international scope of this offense.
Once it's been established that the recipient is being framed, the police--and the FBI--turn their attention to finding the actual perpetrator. The use of the postal service makes the frame-up a federal crime.
This is actually how the FBI actually cracked one of the more infamous child porn rings a few years ago--some idiot tried to frame his neighbor over some stupid dispute and they traced it back to him quite easily.
The classic Japanese serial novel Musashi ( http://www.amazon.com/Musashi-Epic-Novel-Samurai-Era-ebook/d... ) includes a fairly disturbing subplot about the protagonist's reputation being trashed by a little old lady of no significance who follows him around insulting him to anyone who will listen. Despite the fact that no one knows her, and many significant and influential people know (and like) him, this prevents him from landing a respectable job.
> The evidence that petitioner was ready and willing to commit the offense came only after the Government had devoted 2½ years to convincing him that he had or should have the right to engage in the very behavior proscribed by law.
Jacobson was let off on grounds of entrapment; the reasoning was that the government specifically persuaded him to do what he otherwise wouldn't have done (or at least, what it could not be reasonably shown that he otherwise would have done). It's not obvious that that has much to do with whether he was or wasn't aware that child porn was illegal; the fact that the entrapment campaign included political literature protesting government intrusion tends (IMO) to suggest that he was.
Legality does get coverage as an issue, but it seems to be mostly (again, all I did was read the wiki article) as a way to show that Jacobson wasn't a suitable target for the entrapment campaign in the first place; the argument went that buying legal child porn doesn't demonstrate that he's likely to buy the same child porn after it becomes illegal.
The successful prosecutions I've read about involved three things, 1) an opportunity, 2) an awareness of the legality, and 3) the follow through even when there is no reasonable doubt.
Bittorrent is a good example here, and cassette tapes are as well. All of the outward facing material from these folks are focused on legitimate uses of the service, it doesn't keep people like cassette makers from being sued, but it gives them a pretty credible defense. In the linked article you mentioned using Turtl specifically to avoid copyright enforcement, a judge or jury reading that could be persuaded that you intended to facilitate copyright infringement and that intent would make you liable for any copyright infringement that occurred by anyone using the Turtl service. The point I was trying to make is that you are doing the prosecution's job for them when you write
"So how does Turtl deal with copyrighted material?
We don’t. We don’t know what you’re storing. Neither do copyright holders. Neither does the government.
That’s how we like it =]"
It will not be difficult for a prosecutor to use your words to a Jury and show that you like that people can violate copyright with your service and that you made the service so that they could.
And once the prosecution has made the jury understand that, you will be convicted of abetting copyright infringement and either broke for the rest of your life paying off an infringement judgement from hell, or serving time in prison.
All for stuff other people did using your service, because you made it so they could. See how that works?