To be fair, groups on both sides of politics do this all the time, in fact change.org campaigns basically send a million copies of the same e-mail (with only the sender's name changed) to "targets" and we don't seem to think there's anything wrong with that. I've seen many many LGBT campaigns targeting conservative websites and facebook pages with copy-and-paste content as well.
Also, calling this "brigading" is a bit of a reach, given it seems that real unpaid people are copying and pasting the comments in their own names. But then again, if these people were pro-neutrality, Vice would probably be calling it a "grassroots internet campaign".
What's good for the goose...