According to reports in Video Business and the Journal Gazette, four U.S. senators sent a letter to Patricia Vance, President of the Entertainment Software Rating Board (ESRB), regarding the "reliability" of the video game industry's ratings.

Sens. Joe Lieberman (I-Conn.), Hillary Clinton (D-N.Y.), Evan Bayh (D-Ind.) and Sam Brownback (R-Kan.) prepared the letter, which calls for a "thorough review" of the ESRB ratings system.

The letter highlighted the difference between the British Board of Film Classification's decision to ban Manhunt 2 versus the ESRB's reduced rating of Mature for the revised version of the game.

"We have consistently urged parents to pay attention to the (board's) rating system. We must ensure that parents can rely on the consistency and accuracy of those ratings," the letter said.

The senators also voiced concern about the effect that the motion-sensing Wii controller could have on children in games like Manhunt 2. They said it "permits children to act out each of the many graphic torture scenes and murders" and they suggested that the ESRB take the Wii controller's motion capabilities "into consideration" for rating future games.

The letter goes on to complain that "there appears to be a lack of information, to the public and developers, why a particular rating is given or changed. ... Why is information regarding rating changes or reasons for decisions unavailable, except for content descriptors, to the public?"

Ultimately, the senators want the ESRB to undergo a review. "In sum, we ask your consideration of whether it is time to review the robustness, reliability and repeatability of your ratings process, particularly for this genre of 'ultra-violent' videogames and advances in game controllers," they stated.

GameDaily BIZ has contacted the ESRB for comment, and we'll bring you their statement once it's available.