Via Google Blogoscoped, Meta tag abusers face 20 years in prison from The Register covers how a new law in the US might land some people using meta tags in trouble, if they are trying to mislead children.
Specifically, the law says "whoever knowingly embeds words or digital images into the source code of a website with the intent to deceive a minor into viewing material harmful to minors on the internet shall be fined under this title and imprisoned for not more than 20 years."
Meta tag controls were added to the Stop Adults Facilitating the Exploitation of Youth (SAFETY) Act. Now we all know, meta tags have almost no impact on the rankings of a page, but anyone putting those types of keywords in their meta tags most likely are trying to do it with the intent of improving their rankings for those keywords.
See also Danny's past post, New US Child Protection Law Might Make Webmasters Second Guess What They Write.