Tumblr account terminated?

That's strange. Sorry I'm only just seeing this now! Did 당신 ever find out what caused this to happen?

One possibility, I suppose, is that 당신 might have the same external IP address as a tumblr user who got banned for life. Even though external IP addresses are supposed to be unique, there's really only so many of them and sometimes freak things like that happen. However, they also change from time to time. 당신 might find (if 당신 haven't already) that if 당신 try to create an account again, 당신 will have no problems.

(BTW I've apparently shared external IP addresses with people from 일본 and New Zealand before. I live in England.)

It could have been something else of course, but like I said, it's worth trying again if 당신 haven't yet. Whatever it was, it could have easily just been an in-the-moment freak thing that will never happen again.