Also, brutally murdering Santa Claus in front of a bunch of pre-schoolers. And maybe some anal probing. In all seriousness, since there's no readily available proof that the V have done anything wrong, there's not much that the 5th can say. There are some people who recognize that the pattern of V actions indicates motives other than those that they profess, but even they have no proof that the V are doing anything wrong - only indications that there's something shifty going on. For the 5th Column to even start to prove anything they'd have to admit some of what they were doing, or the V who are members of the 5th would have to come forth. And even if the V resistance came forward, Anna would say that they're the terrorists, they're the ones that don't want peace and harmony, and a large part of the human populace would believe her.