Stranger VPNs: Investigating the Geo-Unblocking Capabilities of Commercial VPN Providers.

Commercial Virtual Private Network (VPN) providers have steadily increased their presence in Internet culture. Theirmost advertised use cases are preserving the user's privacy, or circumventing censorship. However, a number of VPN providers nowadays have added what they call a streaming unblocking service. In practice, such VPN providers allow their users to access streaming content that Video-on-Demand (VOD) providers do not provide in a specific geographical region. In this work, we investigate the mechanisms by which commercial VPN providers facilitate access to geo-restricted content, de-facto bypassing VPN-detection countermeasures by VOD providers (blocklists). We actively measure the geo-unblocking capabilities of 6 commercial VPN providers in 4 different geographical regions during two measurements periods of 7 and 4 months respectively. Our results identify two methods to circumvent the geo-restriction mechanisms. These methods consist of: (1) specialized ISPs/hosting providers which do not appear on the blocklists used by content providers to geo-restrict content and (2) the use of residential proxies, which due to their nature also do not appear in those blocklists. Our analysis shows that the ecosystem of the geo-unblocking VPN providers is highly dynamic, adapting their chosen geo-unblocking mechanisms not only over time, but also according to different geographical regions.