https://techcrunch.com/2018/06/05/fcc-has-a-redaction-party-with-emails-relating-to-mystery-attack-on-comment-system/

You may remember the FCC explaining that in both 2014 and 2017, its comment system was briefly taken down by a denial of service attack. At least, so it says — but newly released emails show that the 2014 case was essentially fabricated, and the agency has so aggressively redacted documents relating to the 2017 incident that one suspects they’re hiding more than ordinary privileged information.

As a very quick recap: Shortly after the comment period opened for both net neutrality and the rollback of net neutrality there was a rush of activity that rendered the filing system unusable for a period of hours. This was corrected soon afterwards and the capacity of the system increased to cope with the increased traffic.