Money Laundering charges, just like Kim is being charged with, being brought against them will have them drop file-hosts. PayPal and their Parent Company Ebay will not risk all the other money they take in over what they take in from file-hosting.
It's coming. It looks like Oron is done on PayPal others will follow. Why do think some hosts closed their programs ans cleared their accounts, it was done before their accounts were froze or terminated.
It was part of the complaint in the Universal lawsuit by Mega Upload that all file hosts used PayPal to send and receive payments and listed them. This is going to help or hurt people depending on who you are and what you are doing.
Read about stuff other then uploading and file hosting, do a little searching, the information is out there you just got to look for it.