As an online Poker player, the most important factor for me is to make sure that all my co-players within the table is a legit person and not a bot. It is my most concern of all things in poker and until I don't know how to verify it unless they are chatting in the chatbox. 
Well you can be playing with a bit while your opponent chats with you. It's just difficult to verify from he other side unless you use video chat perhaps that's the only way and I think that's difficult to achieve at this time of online poker gambling development.
Collusion is detectable.