Playpen had over 215,000 users, over 117,000 total posts, and more than 23,000 sexually explicit images and videos of children. The FBI seized and continued to keep Playpen online for 13 days, during which over 100,000 unsuspecting users visited the site while it was under the FBI’s control. Yes, 1,300 true IPs were identified, but only a mere 137 people out of more than 215,000 total users (only 0.06%, less than 1/10th of one percent) were actually charged with a crime.
http://www.usatoday.com/story/news/2016/01/21/fbi-ran-website-sharing-thousands-child-porn-images/79108346/
The only people that the FBI caught were the extremely "low hanging fruit" so to speak, and while those users may have been caught through the use of an exploit, that exploit only got through as a result of their negligence to properly configure their browser according to the specifications and guidelines set forth in the Tor browser guide: http://tutorneunixbasq6.onion/welcome/TorBrowserGuide.html
If you take the time to encrypt your computer and your drives, to update your software regularly, to configure your browser properly, and to not trust or give out any identifiable info about yourself to anyone, then you have absolutely nothing to worry about.
In most instances, these busts are in fact epic failures for law enforcement, which has come under considerable scrutiny for their questionable tactics of illegally continuing to run these child porn sites themselves for weeks or even months, while they desperately try to identify the sites users. The fact that they were only able to charge 137 people, which is a extremely negligible and insignificant amount, clearly indicates the futility of these kinds of endeavors. Even if the entire 1,300 identified IPs had gotten busted, it still would only be slightly more than one half of one percent (0.60%), which does not by any means justify the astronomical expense that this operation cost the tax payers, or the further ongoing multi-billion dollar expense of building, staffing, and maintaining the prisons needed to incarcerate and feed all these people for decades, often solely for nothing more than the downloading and/or possession of mere images and videos..
Bigot assholes like the OP may be happy to see pedos get locked up, and LEA of course likewise likes to brag about how this was a major win for them, but anyone that does the math will quickly come to realize that Law Enforcement has already lost the war on child pornography. There are more than a dozen child porn sites which exist on Tor alone at any given time, and with nearly a quarter of a million users per site, most of whom will eventually further disseminate this content themselves at some point; this alone equates to an exponential self replicating distribution scenario that simply can't be stopped. The overall arrest and conviction rate would have to exceed 50% for Law Enforcement to even make a dent in this largely victimless crime, and I assure you that it is nowhere near that, and never will be.
Child pornography laws are nothing more an enormous waste of financial resources and man power that could be far better spent elsewhere, and is just one of the many fruitless issues of financial waste that is contributing to driving America closer to economic collapse. We are simply never going to eliminate child porn any more than we'd be able to eliminate tobacco, alcohol, or firearms, which by the way all happen have a far greater percentage of harm or violent crime associated with them.