post userid in hidden location?

[cyclical]

There is a user registered on our forum that is using some form of bot that copies all the threads from our forum and post it to another website.

In order to see threads on our board one has to be registered/logged in, so whoever is doing this is using a registered account to copy all his.

Anyone want to throw in their .02 cents on a way to throw in some code that displays a user's id number after a username? I am thinking ill make a new temporary user, and if possible add code that displays the userid for whoever is viewing the forum after the username. Then when the user logs in and copies all the thread information it will copy the temporary username WITH the above code that will tell me who was the one viewing.

So everyone would see the if the username "Temporary"+"userid". And the culprit would give themselves away.

Can anyone give me some clues to the above?