In its sixth follow-up report to the U.S. Congress regarding the entertainment industry's marketing of violent material to children, the Federal Trade Commission noted concerns with the widespread availability of age-inappropriate mobile content.

Though the FTC commended the games industry at large for a reduction of mature-rated game advertisements targeting children and the effective enforcement of ESRB ratings, this marks the second straight year the organization has specifically commented on content available for smartphones and other mobile devices.

"Given the sheer volume of game applications currently available for mobile devices and the dramatic rate at which applications are proliferating," the report notes, "in the near term, responsibility falls on wireless carriers and individual publishers to provide content information and effective parental controls."

Analyzing the websites of several major mobile carriers, the FTC found that AT&T, Sprint, and Verizon offer no age rating information for their mobile games. Nokia displays age ratings and content warning icons, while games available in Apple's App Store feature specific age designations and content descriptors.

The FTC warns that these varied ratings criteria could cause confusion with the ESRB ratings system used by console and PC games. The organization pushed for more specific and clearly-labeled content warnings for mobile applications.

"Although mobile game sellers should be commended for instituting rating systems for their products," the report reads, "the proliferation of different systems has the potential to create consumer confusion with the ESRB ratings, a system with which parents are already familiar.

"Further, it is important that these alternative systems be credible and comprehensive. For the time being, however, these new systems, coupled with effective parental controls, should assist parents in monitoring the content their children play on mobile devices."

The FTC recommends that parents personally assess any mobile games downloaded by their children, and notes that it will continue to monitor developments in age ratings for mobile content.