It is unlawful for any person to import, export, transport, sell, receive, acquire,
possess, or purchase any fish, wildlife, or plant taken, possessed, transported, or
sold in violation of any Federal, State, foreign, or Indian tribal law, treaty, or
regulation.
Thank you for the correction.
However, the big one I would look at in current times for most people is violating web site terms of service.
My point is that the mentality is "Show me the man and I'll find you the crime."
Another way to look at it is you aren't, but should you come to the right peoples attention, they'll figure out how to bend the rules enough so that you are.
No way of really knowing until laws are rolled back, simplified, and followed both from within the confines of the letter of the law and the spirit thereof.
http://en.wikipedia.org/wiki/Computer_Fraud_and_Abuse_Act
Try (a)(2)(C) on for size. If you have a jailbroken phone, its manufacturer might claim that you have unauthorized access to information on a protected computer, even if you are its owner (that's exactly what Sony argued against George Hotz, and they settled out of court, so we'll never know what the courts would have said about that argument). If you have any computer in your house that you modified in a way the manufacturer did not authorize, similar arguments may apply.
However, your luck is in. Now you can just ask the NSA...
Your examples aren't very strong anyway.
Having sex before the age of 18 is usually not statutory rape, if the person you're having sex with is also under 18.
Very few copyright violations meet the standard for criminal charges. Casual copyright violation is not a felony.
You don't have to report anything on your tax return when you sell personal items for less than you originally paid for them. And not all tax code violations are felonies anyway.
Etc.
* Illegal downloads.
* Forwarding a corporate email.
* Some weird term of service in one of the dozen "I read and accept these terms" check-boxes you clicked.
It's also very easy to trivially commit wire fraud.
Two felonies there.
(Who knows, the MPAA and RIAA might be up on Capitol Hill as we speak begging for access to this data.)
For example, see the honest services fraud charges against Jeff Skilling (of Enron fame), on the idea that anything dishonest any corporate executive might do would be depriving the corporation of honest services. Now the Supreme Court reversed Skilling's conviction on the grounds that this was just too vague and that honest services fraud was limited to kickback schemes and the like.
However consider many more:
Lori Drew was prosecuted for unauthorized access to computer servers for violating the terms of service of MySpace (iirc). The subsequent directed verdict of acquittal (after the jury convicted) however did not really eliminate the possibility of ToS violations turning into federal felonies. This was not covered in the book but it is worth noting.
Many of the examples in the books are profession-related. Silverglate goes into detail on the Hurwitz narcotics case where a doctor who operated in line with emerging best practices for chronic pain management was tried and convicted of drug trafficking on the grounds that he had statistical knowledge of the likelihood that at patients might resell the drugs on the street. Hurwitz's conviction was later vacated, but they tried him and convicted him again of a smaller set of charges.
He goes also into medical billing disputes (I have family members who have been on the losing side of these regarding the government and can attest that these are still significant issues).
Another case he does not cover is the Joe Naccio case (covered in the link).
Another case he does not cover was that of my mother's uncle, who they accused of purjury for claiming never to have been a Communist, when their evidence of his lying was that he was legally representing the Communist Party USA and others as a lawyer. They lost that case but came back one tax issue after another until they found something to stick.
There are cases after cases to those of us who follow these things. It is a systemic problem.
Keep in mind that under some of these theories of law, checking Hacker News from work when you should be working is a federal felony, and if not honest services fraud, certainly something they could try you with for wire fraud (it is financial in that you are billing your employer for your time!). Moreover if you check a site for non-work purposes which has a note in the ToS which says that unlawful use is prohibited, then you have committed felony computer trespass (because you "accessed" their servers in excess of authorization provided by the ToS in pursuit of criminal or tortuous ends).
TL;DR: What felonies you commit are unimportant. If they want to, they will find something.