As they put it, any cyberattack against a federal agency is "very serious." It denied the public their chance to influence a major decision, however temporarily. That, in turn, could "call into question" the integrity of the FCC's rule process. To put it another way: whoever's responsible tried to undermine the American system of government, and that will always warrant a closer look.

McCabe has been asked to respond no later than June 23rd. It's not clear how likely he is to take action, and it's entirely possible nothing will come of this. Senators love to send letters expressing their concern about weighty topics, but it's sometimes a purely symbolic gesture. Also, it's safe to say that the security of the FCC's comment system isn't the most pressing issue on McCabe's plate at the moment. If the FBI does agree to an investigation, though, it would be more than a little unusual. Effectively, the bureau would be tasked with calling the FCC's bluff -- it would be challenging the sincerity of a regulator that, to some, appears more interested in forcing a predetermined agenda through the pipeline than listening to the people it's supposed to serve.