I paid the NoScript guy $5 once with PayPal, many years ago. For some reason, that transaction caused my PP account to be frozen. I called PP and they told me

I paid the NoScript guy $5 once with PayPal, many years ago. For some reason, that transaction caused my PP account to be frozen. I called PP and they told me "we can't tell you why your account was locked, because that would give people information to help avoid our fraud detection". I had used this account to buy thousands of dollars worth of stuff on eBay, and they froze it for a $5 transaction. The risk is real.