In the wake of the Snowden revelations, there’s been a lot of new interest in Virtual Private Networks (VPN).

A VPN service works by creating a secure, encrypted network that extends across the public Internet, allowing users to communicate securely with remote systems. VPNs have been used for corporate networks – which are often distributed across many physical locations – for years.

While a VPN service can be set up by anyone using open source software and network hardware, a simpler approach for typical users is to use one of the many VPN service providers currently available.

With so many people now depending VPN services, TorrentFreak wondered just how private those services really are, and came up with a list of questions for VPN providers. For example, some VPN providers keep logs of user IP addresses, which – when handed over to the NSA – could lay bare your supposedly private communications.

You can find the results of TorrentFreak’s investigation on their web site.