AT&T has blocked its billionth unwanted robocall using a new program that detects violators through network data analysis.

The AT&T fraud management team and AT&T big data scientists created the system. It examines more than 1.5 billion calls each day for patterns that indicate robocallers. It then drills down on suspicious activity that may be illegal or forbidden. One example is multiple short-duration calls to numbers on the National Do Not Call list.

AT&T staff examines a preliminary list of suspected robocallers daily. They conduct further research to avoid suspending legitimate automated calls, such as school districts or others who send large volumes of recorded messages.

AT&T is blocking robocalls in cases where our business contracts allow us to block impermissible traffic. The FCC recently proposed new rules to give carriers even more flexibility to "target and eliminate unlawful robocalls." These new rules could allow carriers to stop literally billions more unwanted calls from reaching consumers.

In recent weeks, the AT&T program has been averaging 12 million blocked calls per weekday.

"Our data science team took on a challenge to analyze and address the problem. We knew the winners would be our customers," said Jenifer Robertson, senior vice president for technology strategy, AT&T.

The analytics-based blocking program works against those who use the AT&T network to send robocalls. It joins other AT&T efforts that help protect people from receiving unwanted calls.

• AT&T Call Protect is a free service announced in December. It automatically blocks fraud calls and gives screen alerts for suspected incoming spam calls. It works for eligible AT&T wireless customers with HD Voice.
• Our website att.com/fraud has a form where customers can report unwanted calls and texts to help us block future calls.