Thought I should spread the word on this one so that more people who have the same experience will kknow what's going on. It has happened to me two times now, that I get a random message on AIM from a user called something with "Coho" on the end.
First time I did not reply as I understod there was some kind of spam-thingy. Today when I got the message I googled for the user name and found the following post on someone who got contacted by "BoughtCoho".
I found out that the message is coming from a fishing bot system which is harmless as such but is created for confusing its targets. It connects random people by finding AIM-names on sites like (LiveJournal, Xanga, deviantArt, Twitter, etc.) and sends an opening message to both of them.
I thought I give it a try and I did respond to the message to the user called "ChangingCoho". Below is a image of the chat I had with another user. She told me that I appeared as "WhimperingCoho" on her screen. She told me it's okey to post that image as it would be useful for other people who had this happen to them.
If you want to read more about this experiment you can visit the Livejournal-group by the people behind it. There's a link for a page where you can request a robotic fish entering your AIM name. But be warned the initial message can me very rude.