So I guess I spoke too soon about these "bots" because a few days ago I was on the front page and I, too, had really weird looking grey users. The first one was just a number... you can check out the profile the username is "21011992". It looked familiar to what I saw in the other girls' rooms the other day, they were just top 10 so they had maybe 5-8 of these weird number usernames. I don't use bots so my only thought is that MAYBE this is a real user OR this could be a bot recording my show. Everyone one of my shows (as do a lot of girls) gets recorded and placed on 100s of sites. Maybe some of these bots are these recording devices... just a thought.
They are programs/script files that run, albeit on a relatively larger scale here. Without getting too much into the nitty gritty of how the internet works, I can write a program that "visits" a web page. If you've ever heard of webcrawlers or "spiders" that's essentially what those are. That's the very basic function though.... You can also write programs that mimic form submissions (entering in details and clicking a submit button) or other tasks.
I've not written one like this myself, but I imagine it's relatively straightforward to write a program that goes to site X, submits credentials, then do Y.