On Wednesday, the Federal Trade Commission announced another contest to design a system to "identify unwanted robocalls received on landlines or mobile phones, and block and forward those calls to a honeypot."

The agency will select "up to five contestants" as part of what it’s calling "Robocalls: Humanity Strikes Back."

The first qualifying phase launches Wednesday and runs through June 15, 2015 at 10:00pm Eastern Time, while the final phase concludes at DEF CON 23 on August 9, 2015.

"We’re using many strategies to fight robocalls, including law enforcement, education, and crowd-sourced innovation," said Jessica Rich, the head of the FTC’s Bureau of Consumer Protection, in a statement. "Following the success of our previous robocall challenges, we’re once again seeking expertise from the public to put a new tool in consumers’ hands and to develop technology to help law enforcement and other partners investigate these calls."

The FTC will choose five contestants from the first round who will then will advance to the final round. The ideas will compete for a top prize of $25,000 at the Las Vegas conference.

Back in 2013, the FTC split a $50,000 prize between three winners who devised robocall blocking systems that might help end the scourge forever. Two of the winning proposals detected illegal robocallers and disconnected the call before it could get through to consumers. The third could build a database of bad numbers by having consumers report robocalls. The agency held a similar contest in 2014.

The FTC did not immediately respond to Ars’ query about what happened to the tech that came from the first two contests, but we'll update this post if we receive an official response.

UPDATE Wednesday 9:47pm CT: Cheryl Warner, an FTC spokeswoman, wrote Ars: