On Wednesday, the would remove the DUI checkpoint apps. "Drunk drivers will soon have one less tool to evade law enforcement and endanger our friends and families," the senators said in a statement. "We appreciate RIM's immediate reply and urge the other smartphone makers to quickly follow suit."

But the apps in question contain publicly available information provided by police departments as well as reports from drivers, said Morgan Reed, ACT's executive director. The social-networking and law enforcement information makes the apps very popular, he said.

"While I applaud the senators for seeking to curb drunk driving, their criticism of online travel apps misses the point," he said. "Law enforcement authorities have embraced these services, expressing their strong approval for products that reduce speeding and improve traffic safety."

The apps provide drivers warnings about other potential roadway problems, Reed said. "Any one of the programs' users can submit a warning about a traffic obstruction as simply as e-mailing a friend or posting a message on their Facebook profile," he added. "The suggestion that the government should compel Apple, RIM, or other mobile application stores to block programs that simply allow users to report information based on location is misguided at best. Having the government act as arbiter of which products should be sold in stores is a slippery slope that few would welcome."

Asked if the senators' letter amounted to the government compelling action of the smartphone makers, ACT spokesman Jonathan Godfrey suggested it did. "When the Senate majority leader [Reid] and his senate colleagues send a letter urging you to do something, implicit is that they can have hearings and examine legislative fixes if you don't address their concerns," he said.