Two US senators are urging the mobile phone industry to fight robocalls and texts by creating a database of phone numbers that have been reassigned from one customer to another.

Reassigned numbers are one of the major contributors to unwanted calls and texts, and carriers haven't done enough to fight the problem, said US Senators John Thune (R-S.D.) and Ed Markey (D-Mass.). The lawmakers wrote a letter today to CEO Meredith Attwell Baker of CTIA–The Wireless Association, a lobby group that represents AT&T, Verizon Wireless, T-Mobile USA, Sprint, and other mobile carriers.

Thune and Markey "believe wireless carriers may have an opportunity to provide consumers and businesses more needed relief by establishing a reassigned numbers database, containing a list of cell phone numbers that have changed ownership," they wrote. "Periodically, consumers receive unwanted robocalls and robotexts because the previous holder of the phone number provided consent. Not only are robocalls and robotexts to reassigned numbers a nuisance to consumers, but they also create liabilities for calling parties."

Thune and Markey asked the CTIA to provide information on how wireless companies could compile reassigned numbers in a database and how they could provide access to the database so that callers (often telemarketers) can determine whether a number is still assigned to the original owner. The senators also asked whether the cost of the database can be covered by charging a fee to callers.

AT&T CEO Randall Stephenson recently claimed that AT&T doesn't have the "authority" to implement new robocall blocking technology in its mobile network, even though the Federal Communications Commission clearly stated last year that carriers have the "green light" to offer robocall-blocking services to consumers.

Despite AT&T's reluctance, Thune and Markey said they appreciate the work CTIA members "are undertaking to implement market-based solutions that consumers can use to stop unwanted robocalls and robotexts."

When contacted by Ars, a CTIA spokesperson provided a statement from VP Brad Gillen, who said, "Unwanted calls and texts are a consumer issue the wireless industry works hard to address and we look forward to working with Senators Thune and Markey to help address this challenge together."