Not necessarily. When theymos stepped in and dealt with the Yobit spammers, he simply wiped all Yobit signatures and banned them for 60 days. He wasn't able to ban the signature campaign itself, since it is run off-site on the Yobit exchange, and there was no manager to ban as far as I am aware. However, you can't argue that what he did didn't work - the spam was horrendous and disappeared instantly.

I don't think it's a huge issue if these campaigns move their management off-site. If we start banning campaigns and their participants which are largely spamming, future campaigns will very quickly learn to employ a manager who actually pays attention to post quality.