This kind of situation has been happening, so it's good to stay alert. It would be interesting to create a list of these suspicious accounts and share it with the community managers here on Hive. It's not the best solution, but it might help in some way. Here in our Brazilian community, it's easier to control this kind of abuse because the volume is small, but I believe in larger communities this is a major headache. If you need anything, I'm available to help.