[citation][nom]wiyosaya[/nom]What is encrypted is the packet payload. Headers cannot be encrypted because IP traffic routing would not work.Through a VPN, though, what will be in the unencrypted header is the IP address of the VPN server and the client, i.e., downloader's IP. What would not be in the header is the source IP of the server where the file is located.Going through a VPN like this would make it difficult at best for an ISP to trace based on the IP of a file hosting site. It will not, however, mask high-volume traffic - as others have pointed out to me - to any computer that is downloading mass amounts of data.Absolutely correct. Thanks for pointing that out.[/citation]
When someone uses VPN to conceal piracy, the ISP does know that large amounts of data is transferred between the client and the VPN server. But that's it! Since transferring a large amount of data isn't illegal, the ISP is powerless.
At work for example, everyday we store a backup of our data on a remote server through a secure VPN. At the end of the month we have quite a large amount of data transferred using a secure VPN, this doesn't means I'm doing anything illegally.