I have two question, first
http://privateinternetaccess.com/ is hosted in the US, which means if they get a subpoena they have two choices, either give the US authorities what they want, or go to jail and have there assets and servers forcibly ceased. You honestly think they are loyal enough to their customers to go to jail?
Second question is how is it anonymous? If they don't provide solid proof that they purge all server logs and that the hosting companies they use also purge all server logs then they are not anonymous and the OP is spreading misinformation by recommending this company.
