That's certainly one of the knottier points of copyright law, in which I am no expert.
The Copyright, Designs and Patents Act 1988 (as amended) defines works in which copyright subsists as original literary / dramatic / musical / artistic works (s. 1(1)(a)), sound recordings / films / broadcasts (s. 1(1)(b)) and the typography of published editions (s. 1(1)(c)).
The rights subsisting in copyright works are defined in s. 2, and the definitions of the types of works are expanded in ss. 3-5B. s. 6A extends copyright protection to certain satellite programming uplinked from a non-EU country that lacks EU equivalent copyright protection.
This means that there is no 'born copyright' (for want of a better phrase) in a sporting fixture. If you can find a vantage point to film it with a long lens without trespassing, you can do what you like with that coverage in which you own the copyright.
Those responsible for sporting fixtures operate by admitting only broadcasters to whom they have granted rights, and making it a condition of entry (and therefore enforceable via contract law) that permission to enter the ground is conditional on not making any recording or broadcast of the event. In reality, there's little they can do about people filming using their mobile phones, but that's not broadcast quality anyway (though it is a pain when some idiot insists on holding up their mobile phone in front of you, and dodges across your field of view every time they are blocked, especially if you are a wheelchair user like me).
However, the material filmed by the organisers or directly by the rights-holding broadcasters is subject to copyright. I fully agree with the ruling of the CJEU in the case mentioned earlier in this thread - the EU freedoms permit the use of legitimate subscriptions to services in other EU countries, with any breach of territorial restrictions (in either the agreement between the sporting organisation and the broadcaster, or because someone is selling the subscriptions in a country prohibited by the terms of the contract) being a purely contractual matter.
The enforcement of territorial rights on the Internet is notoriously fickle. The geolocation databases are not all that accurate, and there are plenty of ways to present your traffic as originating in another country.
I strongly feel we need a much more holistic and liberated view of rights in this Internet age. I'm very happy to pay for the content I use, and am heartily fed up of petty restrictions imposed by rights holders.
I have little interest in sport, and am adequately served by the sport channels I have as part of the Virgin XL package (including BT Sports HD and Eurosport HD) for the limited amount of sport I watch.
I notice a lot of petty restrictions with music. I subscribe to Spotify Premium and make quite heavy use of it. I'm fed up of albums on Spotify with tracks missing, even for users on the paid-for Spotify services. Sometimes the missing tracks destroy the integrity of the whole work - I've come across musicals with tracks missing, though albums in the genres I mostly listen to (primarily the kind of material you'd find on Radio 3) are usually complete.
The problem of missing tracks is likely to be because something somewhere in the various rights chains (copyright in the words and music, copyright in the performance, record company copyright in the finished product) didn't anticipate the modern Internet age and either granted the online rights to a different party or didn't grant the rights relevant to online use to anyone. I know there is controversy about how little streaming music services pay per play, which means artists make very little from streaming plays compared to CD and download sales, but there's only so much users will pay for these services and if they feel they are not value for money, there's plenty of pirated music swilling around on the Internet.
More annoying still is when tracks that were on Spotify disappear over time. This is less easy to justify and sometimes feels like a bait and switch to get users to like an album before being forced to buy the album or download to continue listening. A notable example of this was the first disc of the "Isles of Wonder" double CD of music from the London 2012 Olympics - the one with the music from the opening ceremony itself. When it first appeared on Spotify, it was almost complete - I think there were two tracks missing, presumably for rights reasons, one of which was the "Chariots of Fire" arrangement (nothing special, as the Mr Bean bit rapidly grows tiring, and the original Vangelis version is on Spotify anyway, both the full 20 minute original and the more normal 3.5 minute edit). All the specially composed music from the opening ceremony was on Spotify initially.
Over time, more and more disappeared. After a few weeks "Caliban's Dream" disappeared (the track from end of the ceremony when they lit the cauldron), which was the most popular track on Spotify, if I remember correctly. More recently "And I Will Kiss" disappeared (the track from the Pandemonium scene that started with all the drummers). Those two tracks together were arguably the two musical highlights, not least as most of the rest of the material used was arrangements of well-known material or material which had previously been released commercially rather than being wholly original.
Looking on Spotify now, I can't find the album at all. The last time I checked, there were only about four tracks left anyway.
I'm sure many of the same frustrations apply to sports fans. For commercial and competition reasons, sports are being spread across a multitude of services, with all manner of restrictions around them with the aim of gouging money from fans. It seems to have escaped the idiots responsible for competition regulation that forcing the Premier League live rights to be split between two or more broadcasters would not break Sky's monopoly, but would merely drive up the price Sky pays (and therefore charges its customers) to ensure it secured the bulk of the rights, whilst creating a second commercial competitor to Sky to which avid football fans would also need to subscribe.
If you want to follow the Premier League live in HD using the official UK rights holding broadcasters, you need a Sky Sports subscription plus Sky's HD supplement (whether on Virgin or on the satellite platform - there are no HD supplements normally on Virgin but Sky insisted on an HD supplement for the HD versions of the Sky movies and Sky sports channels). You also need BT Sports HD, which means Virgin's XL package, or a BT Broadband product and pay the HD supplement to have the HD channels activated on your Sky card, or stream in HD from BT if you have a good enough BT broadband connection. I may have got the details of some of the packages and supplements wrong, as they are always changing - but that's part of the problem.
Charging HD supplements is particularly galling considering that the HD versions of the channels are on the broadcast platforms anyway.
If I still followed Formula 1 and wanted to watch live in HD, I'd be out of luck. Some races are on BBC One HD - but for those races on Sky F1, the only answer is the Sky platform, as Sky will only let Virgin have the SD version of Sky F1. I have no line of sight to any of the geostationary satellites due to a line of ancient and protected trees running across the south of my garden, which means I cannot watch any of the satellite based services. That's part of the problem - not everyone can access every service.
Instead of buying what you want, you are forced to subscribe to multiple packages (including a whole bunch of stuff you don't want), often across multiple platforms or channel bundles. There's some channels I watch occasionally on Virgin where the sole HD rights appear to have been sold to the satellite platform - in particular History HD has been on the satellite platform for a long time but shows no sign of appearing on Virgin. I'm fairly sure Sky are still refusing to let Virgin have Sky Atlantic HD, too (though it's of no interest to me as I don't pay for the Sky Movies pack).
It's no wonder these petty marketing restrictions that massively inflate the charges people are expected to pay drives people to online services which source material via somewhat dubious routes. Many people simply haven't got £40+ per month to spend on sport channel subscriptions.