It's disingenuous enough when the word 'stealing' is re-purposed in discussions about copyright infringement, since it is very doubtful that every copy of a shared file resulted in an actual loss.
In this case, though, it seems easy enough to establish that the BBC has provided no way to compensate them for viewing their content from the United States. You might be "stealing" bandwidth in some sense, but I don't think it's fair to characterize the content as stolen in this case. The third party (VPN/proxy provider) is paid for network access just like you pay an ISP, not for the content itself.
I doubt it's easy, but they've been working on it for a while now and it should be available fairly soon.
I agree that it may not be fair to characterise the content as 'stolen'; I chose to use that term out of laziness. However, it's definitely not fair to consume the content without paying, either. It increases the financial burden on the UK license payer. Many of the BBC's shows are available to a US audience - you just have to buy them on Amazon, or stream them on Netflix.
I only need a licence if I watch tv broadcast live. Everything is defined in law; the devices used to receive (which include smart phones and computers) and the signals (which weirdly include for example French telly received via satellite). A person could hate the BBC and all its output and never watch it but still need to pay the licence fee.
Personally, I welcome the BBC but the enforcement of the licence has been sub-optimal in the past.
The licence fee made perfect sense when it was created, it arguably has been unfair to consumers since VHS became popular.