Privacy advocacy group Fight for the Future is questioning the Federal Communications Commission’s claims it suffered from a DDoS attack that made it next to impossible for visitors to leave public comments on the agency’s net neutrality rules.

The organization has asked the FCC to release proof it was attacked and questioned the timing of such an event, which happened shortly after a segment on the HBO program Last Week Tonight encouraged viewers to leave comments opposing the commission’s proposed changes to existing net neutrality protections.

Read: Net Neutrality Rules: Title II To Be Reversed Under FCC Chairman Ajit Pai's Plan

“The FCC’s statement today raises a lot of questions, and the agency should act immediately to ensure that voices of the public are not being silenced as it considers a move that would affect every single person that uses the Internet,” Fight for the Future campaign director Evan Greer said in a statement.

According to the advocacy group, there are two possible scenarios that explain the supposed DDoS, or distributed denial-of-service, attack that left visitors to the site without the ability to leave comments.

The first plausible explanation, Fight for the Future said, is the FCC is being intentionally misleading and claiming the surge in traffic directed to the site by John Oliver’s segment on net neutrality amounts to a DDoS attack. Greer theorizes the agency may do this to “let themselves off the hook for essentially silencing large numbers of people by not having a properly functioning site to receive comments from the public about an important issue.”

A second possibility is the site was actually hit by a DDoS attack, timed to launch during or shortly after the segment aired on HBO, to prevent people from commenting on the FCC’s proposed rules changes.

“Given Ajit Pai’s open hostility toward net neutrality, and the telecom industry’s long history of astroturfing and paying shady organizations to do their dirty work, either of these scenarios should be concerning for anyone who cares about government transparency, free speech and the future of the internet,” Greer said.

Read: Net Neutrality Debate: FCC Says Comment Site Hit By DDoS Attack After John Oliver Segment

The organization called for the FCC to release logs of the purported DDoS attack to be reviewed by an independent security analyst to verify the veracity of the agency’s claims.

The FCC has not yet responded to the request.

According to the FCC’s original statement on the attack, its website was hit by an overwhelming amount of traffic beginning Sunday evening. Originally, many attributed that traffic to John Oliver, who dedicated a block of his HBO show Last Week Tonight to encouraging viewers to leave comments on the FCC’s site to persuade the agency to keep intact current net neutrality rules.

The show, a rehash of his 2014 segment that encouraged people to push the FCC to pass the original Open Internet Order, once again called for viewers to comment on the FCC’s site to tell new FCC chairman not to undo the rules as he has proposed. In 2014, Oliver’s attention to the issue resulted in the comment site crashing.