PhantomALERT is produced by a Harrisburg, Penn.-based company of the same name. As of 5 p.m. ET Wednesday, a search for the app on the BlackBerry App World site came up empty. However, the program was still available on Google's Android Market and Apple's App Store.

On Wednesday, Scott again argued that PhantomALERT is "100% legal" and said the senators' concerns were unwarranted. "I think we are misjudged. If they really understood what we are doing and aim to achieve they would actually support us," Scott said in an e-mail.

One trade group agreed with Scott.

"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," said the (ACT), a Washington-based group that claims to represent more than 3,000 small- and mid-sized IT companies. "Taken to its conclusion, that would require blocking apps like Foursquare and Loopt. Having the government act as arbiter of which products should be sold in stores is a slippery slope that few would welcome."

ACT also counts , and eBay among its members.