One of the most potent and controversial tools in the American intelligence community’s arsenal is set to lapse at the end of this year. Section 702 of the FISA Amendments Act of 2008 allows the government to intercept the communications of foreign targets as they cross U.S. soil—including conversations with American citizens. Spy agencies claim it’s a vital weapon against terrorists and should not only be reauthorized but also made permanent. Civil libertarians, however, worry that the law’s incredible scope—targeting some 100,000 people and hauling in hundreds of millions, if not billions, of communications each year—makes it ripe for abuse without significant reform.

Among the law’s most vocal critics have been two senators from opposite sides of the political spectrum: Ron Wyden and Rand Paul. At this Cato forum, they’ll explore how section 702 works and whether it needs stronger safeguards to protect Americans’ privacy. Should a warrant be required to search for citizens’ communications in the vast 702 database? Is it feasible to demand an estimate of how many Americans have been “incidentally” caught up in 702 surveillance—a number that the intelligence community has said it’s unable to provide? And does the foreign backlash against 702 surveillance threaten global Internet commerce? We’ll delve into these questions in a wide-ranging discussion.