John Oliver's passionate appeal to get citizens to complain to the Federal Communications Commission on behalf of net neutrality may have provoked a cyberattack on the government website.

On Sunday's broadcast of HBO's "Last Week Tonight," Oliver ran an impassioned segment (for the second time in his career) on the topic of net neutrality, and why it was necessary for all internet traffic to be treated equally. He called on viewers to comment on the topic using GoFCCYourself.com, which redirected to the official "Restoring Internet Freedom" FCC proceeding.

Among the deluge of commentators were more sinister actors who took down the site, the FCC said.

"Beginning on Sunday night at midnight, our analysis reveals that the FCC was subject to multiple distributed denial-of-service attacks ( DDos )," FCC Chief Information Officer David Bray said in a statement.

"These were deliberate attempts by external actors to bombard the FCC's comment system with a high amount of traffic to our commercial cloud host. These actors were not attempting to file comments themselves; rather they made it difficult for legitimate commenters to access and file with the FCC. While the comment system remained up and running the entire time, these DDoS events tied up the servers and prevented them from responding to people attempting to submit comments. We have worked with our commercial partners to address this situation and will continue to monitor developments going forward."

DDoS attacks occur when sites are bombarded with fake requests, causing the system to overload. As a result, real users trying to access the website cannot go through.

"Neither 'Last Week Tonight' nor HBO were involved in any DDoS attack against the FCC website on Sunday night," HBO said in a statement.

See the "Last Week Tonight" segment below.