Much to the chagrin of many activists but much to the joy of the game industry, last year the Video Game Decency Act (in the United States) found itself dying with a whimper. It was pushed forward largely due to upset over games requiring re-ratings (such as GTA and Oblivion). While it failed to gain enough support, the bill has been re-written and has now resurfaced, aiming to make hiding certain content in a game from ratings a crime:

As reported by GamePolitics.com, Rep. Fred Upton, R-Mich., last week introduced the Video Game Decency Act of 2007 to the House of Representatives, where it was quickly referred to the House Committee on Energy and Commerce. The bill aims to criminalize any attempt to obtain a less-restrictive age-related rating on a game by failing to disclose the game's true contents to the Entertainment Software Rating Board.
Despite the fact tools are already in place to fine and penalize companies that drop the ball or outright deceive the ESRB for ratings, some feel it isn't enough. You can read the gory details of the proposed bill in the original article.