I refuse to believe that there is nothing we can do about this, and we just have to sit and twiddle our thumbs while watching these 100+ (and growing) accounts spam and then start abusing bounties, bumping threads, or being sold. Why, when we have such clear evidence of abuse, do we have to be reactive rather than proactive in tackling it?
DT can't tag them - because this is moderation problem. Moderator can nuke them - but then we will see hundred new accounts.
I don't see any other solution than newbie jail. That will solve many problems and make this forum better place.