The Democratic chairman of the Senate Judiciary Committee on Friday vowed to investigate federal spying programs sanctioned by the Obama administration when Congress returns from its summer recess next month.

Following a Washington Post report detailing thousands of instances in which the National Security Agency broke the rules to collect data, Sen. Patrick Leahy, D-Vt., said Congress needs to demand “honest and forthright answers from the intelligence community.”

“I remain concerned that we are still not getting straightforward answers from the NSA,” Leahy wrote in a statement. “Using advanced surveillance technologies in secret demands close oversight and appropriate checks and balances, and the American people deserve no less than that.”

Leahy said he will schedule a hearing but did not specify when. Congress returns from it’s August recess in early September.

An internal audit provided to the Post by embattled fugitive leaker Edward Snowden showed the NSA repeatedly overstepping its authority, often unknowingly, to spy on people. In one case the NSA tracked thousands of phone calls of D.C. residents because a computer program mixed up the area’s 202 area code with 20, the international exchange code for Egypt. The agency also exceeded the scope of a court order that allowed it to collect data on 3,000 Americans and foreigners living in the U.S.

Snowden's exposure of the NSA’s monitoring of American phone and email records united a coalition of liberal and libertarian advocates who are wary of the growing military-industrial complex. That culminated earlier this month when an amendment from Rep. Justin Amash, R-Mich., to slash spending on the NSA programs nearly passed the House with rare bipartisan support.

The latest revelations have provided additional ammo to opponents of the NSA’s practices.

“Today’s [Washington Post story] reveals NSA privacy breaches,” tweeted Rep. Gerry Connolly, D-Va. “Who is surprised? It’s why I voted for Amash amendment.”