Many people might be familiar with this video, titled "Don't Talk to the Police" which is a two-part talk delivered by Regent University law professor James Duane and a Virginia Beach police officer:

http://video.google.com/videoplay?docid=8167533318153586646&...

It discusses many of the same issues, citing one primary reason for not talking to the police as the tremendous, unknowable breadth of federal law and the fact that you can't possibly know what strange provisions you might be in breach of. Professor Duane quotes Supreme Court Justice Breyer:

"The complexity of modern federal criminal law, codified in several thousand sections of the United States Code, and the virtually infinite variety of factual circumstances that might trigger an investigation into a possible violation of the law, make it difficult for anyone to know in advance just when a particular set of statements might later appear to a prosecutor to be relevant to some investigation."

Duane memorably points out that it's illegal to be in possession of a lobster of a length that is too short under Honduran law, even "if you acted in self-defense."

I strongly recommend it as an extremely entertaining and informative talk to anyone who hasn't previously seen it.