All of the evidence is in the Bitshares blockchain. This is public and can be accessed.
Who actually owns the bots, I don't know. Given the activity of the bots, in my analysis it seems that it is really obvious -in my opinion- the main purpose is to drive up volume. Yes, I have more evidence and no I am not posting it all here right now. I will give a couple as samples though. Here is a few transactions...
Here is a count of some of the transactions. The first line should be interpreted as in my limited transaction set of 1,759 transactions Audi-7 sold 405 times.
If you look at the who they sold to... it is very similar.