A classified Capitol Hill briefing this week on the National Security Agency’s surveillance programs failed to garner even half of the Senate, according to The Hill.

The briefing with Director of National Intelligence James Clapper and NSA head Keith Alexander was held Thursday afternoon — after many senators had already elected to leave town to get a jump on their Father’s Day weekends.

According to The Hill, just 47 out of 100 senators were there, leaving “dozens” of empty chairs as the intelligence chiefs talked about the U.S. government’s newly-revealed monitoring of millions of phone records and Internet activity.

Senate Intelligence Committee Chairwoman Dianne Feinstein (D-Calif.) expressed frustration at the lack of attendance.

“It’s hard to get this story out. Even now we have this big briefing — we’ve got Alexander, we’ve got the FBI, we’ve got the Justice Department, we have the FISA Court there, we have Clapper there — and people are leaving,” Feinstein said.

President Barack Obama earlier this month defended the government’s monitoring activities and said Congress is kept fully apprised. That prompted some individual lawmakers to come forward to say they personally had been unaware of the surveillance programs.

The Hill said it was not given a list of senators who attended on Thursday, but that both Sens. Johnny Isakson (R-Ga.) and Rand Paul (R-Ky.) were seen leaving the briefing.