On Sunday night, shortly after HBO comedian John Oliver called for people to express support for net neutrality to the Federal Communications Commission, the agency's Web site faltered.
Oliver's remarks apparently spurred people to flood the site with comments. But the FCC said Monday that the crash wasn't the result of too many comments, but of a denial-of-service attack.
Net neutrality advocates are skeptical of that explanation. The group Fight for the Future called on the FCC to allow its logs to be reviewed by independent researchers.
"The agency has a responsibility to maintain a functioning website to receive large numbers of comments and feedback from the public. They can't blame DDoS attacks without proof, they need to fix this problem and ensure that comments on this important issue are not lost," the group stated this week.
Sens. Ron Wyden (D-Oregon) and Brain Schatz (D-Hawaii) are also seeking answers from the FCC.
"As you know, it is critical to the rulemaking and regulatory process that the public be able to take part without unnecessary technical or administrative burdens," the lawmakers write. "Any potentially hostile cyber activities that prevent Americans from being able to participate in a fair and transparent process must be treated as a serious issue."
They are asking the FCC to provide details about any malicious traffic, including how many devices sent malicious traffic to the agency. The lawmakers also have asked the FCC whether it requested investigatory assistance from other federal agencies, and whether it uses any commercial protection services.
Wyden and Schatz also asked the agency how much traffic the site can handle at any one time, and whether the FCC has done "stress testing."
In addition, the lawmakers want to know how the crash affected people who wanted to file comments.
"Did the DDoS attacks prevent the public from being able to submit comments through the FCC's website?" they ask. "Were any comments lost or otherwise affected?"
The lawmakers are asking for a response by no later than June 8.