Why did they try and claim it was a criminal offence?
Yes, that is really, really stupid. Don't just take my word for it:
http://www.citmedialaw.org/legal-guide/circumventing-copyrig...
Note that this is different from saying that it is criminal. Under U.S. copyright law, not every infringement is criminal. In fact, criminal infringements are the exception, not the rule.
So, as far as I know, they did not claim what you say they claim. Unless you have a good citation to the contrary, that is.