Probably just means the normal level of rainbow arrests, which are avoidable. Tie a rope to your dog, wear pants on public roads, don't drive with a busted headlight, don't pass the pipe to a forest ranger.
If he meant something more... hell even with as brainwashed as some people seem, I don't think 'murica could get away with arresting thousands or tens of thousands and not risk major trouble. Rainbow isnt all crusties and bush hippies, you know? And if somehow it did happen, I for one would rather be in the middle of it.