Update: The BBC has been in contact to point out that it has been actively seeking to block people from outside of the UK from accessing iPlayer with regular updates for some time.
"BBC iPlayer is freely available to users across the UK without a VPN, and we also seek to ensure users of private VPNs such as those used by schools and companies in the UK have access."
The BBC has said that it is going to start blocking access to the iPlayer for VPN users. So bad news if you're sneakily catching up on Doctor Who from abroad.
VPNs - or Virtual Private Networks - are a means of funnelling your internet traffic through another location, so that for example, someone in America could watch the iPlayer and the BBC website would think that the person watching is based in the UK.
According to TorrentFreak the BBC said the move was intended to "stop piracy", but could also have the unintended consequence of blocking legitimate UK users, such as those who use satellite broadband (which is sometimes used in remote areas), and anyone who uses a VPN to connect securely with their employer. Then there's also the grey area of what about British expats who still pay the license fee watching from abroad.
VPN workarounds aren't unique to the iPlayer. Many British users in return use VPNs to access the US version of Netflix and other services too.
The move follows the shuttering last month of the BBC's experimental "global iPlayer" service, which made certain shows available to international users willing to pay a monthly fee. Instead, the BBC appears to be pivoting to selling shows internationally for viewing on other platforms such as Netflix and Hulu.
As TF notes, what will likely happen now is a game of whack-a-mole, in which VPN providers work to find workarounds, and the BBC work to ban any new VPN IP addresses from accessing the service. Of course, the entertainment industry could work together to establish new licensing rules now that the market for digital content is global rather than divided by country, that would be far too sensible.