Paypal has closed and locked up accounts for what it considers gambling transactions. I have heard of people getting theres locked for accepting payment for gambling related link sales.
I do not belive they catch everyone, I do not know how hard they try to catch people. I try to never let the words poker, casino, gambling, etc. be mentioned in relation to my Paypal account. I do not want to chance it getting locked.
This is my opinion, based on what I have seen. I have never had my account locked, or closed. I have had my Paypal account for a long time, I remember when that is how I funded my poker accounts.