(read carfully, hope it's not to confuseing)
I have a suggestion,
Required rule reading to register!
To register for TF2 users should have to read the rules...
There is no way to make somebody read the rules...
But you can make them type them, (Thus forceing them to read them)
I was thinking back to how one of my friends would study for tests. He would take his notes, and copy them to another paper... (Memorizing in the process). Which made me think of a typing test I took a while back at this website: http://www.typingtest.com/
While taking the test you cannot copy and paste... (Has some kind of block, so you can only type)
Now to get to the point
When signing up users should have to read the rules,
To force them to do so, make them type them...
Using ideas from above... set up a page with the rules listed on one side and an area to type them out on the other (with the copy and paste restriction)
Probably not all the rules, perhaps a summary
... (This would be part of registration)
Have it set up to accept something like 10% or 20% margin of error
This would definitely discourage spammers from making accounts
I hope I composed that well enough to understand