There is a possibility that this was a botnet that sells followers. I know that this one wasn't into retweeting or linking to anything, though such botnets do exist.
I wasn't able to prove that is the case with that particular network, as there were a number of "following nobody, and nobody follows" accounts. But I've found another that for sure is in the business of so doing. How does one person with only four very banal tweets get 4000 followers? It turns out that his followers are indeed bots. This network I will be collecting too. Maybe it will turn out to overlap.
@paulmd199
PS: I won't insist on the theory that it's government sponsored bot. it could well be commercial, or just run by some jerk.