Back in ye olden days when MD had a PayPal account it was seized because MD is a pirate site and PayPal is legally obligated (in many countries) to not facilitate money transfers to those that break the law.
Edit: before someone says "well xxx does donations via PayPal", it's only a matter of time before they get reported or found out. Then the account will get seized and so money in it at the time will be lost. "Well then just transfer the money out as some as it gets added", PayPal is not dumb to this and will flag accounts that do that kind of thing for further scrutiny. Which usually has the outcome of losing the account.