Don't kid yourself, Lens makes more than enough through advertisers, he doesnt need to charge $5 a month. Also, keep in mind that the reason GFY is a phenominon (sp) is because it has so many eyeballs. If he starts charging, there will be less users, and therefore, less advertising money.
Now to a different topic, Lensman, PLEASE READ THIS THREAD.
http://www.gofuckyourself.com/showthread.php?t=434762
Most of us believe this is a good solution to stopping the surfers and others (goverment agents?) from coming to the board.