As Sen. Rand Paul took to the Senate floor for hours Wednesday for a filibuster, he sparked a separate lengthy conversation — on Twitter.

Paul’s (R-Ky.) filibuster was designed to block moves toward confirmation of John Brennan, the White House’s pick to head the CIA. Paul, who has stressed his concerns over the use of drones targeting American citizens in the United States, promised to “speak as long as it takes, until the alarm is sounded from coast to coast” about the issue.