I don't think that paypal is a SCAM , But I've heard some rumors about scam issue but so far I've its working smoothly 
It's working smoothly only in first world countries. In many countries, it is hell to just have your money back to you after getting it from a different country. I am not saying that it is ridiculous mainly coz what can be used for good, can also be used for something really bad. But the rules for making an account limited should be less negative.
i think the rules are same for everyone and people in America do get their accounts frozen so does people from third world countries if they think something is fishy.This might not be the case, though not on the basis of developed versus developing countries. As I know it, PayPal operating in some country is required to follow local laws, and these laws obviously differ between jurisdictions. Therefore, some actions which are considered illegal in one state or country, for example, selling weed, may be considered as perfectly legit in other countries.