Exact numbers, I can't easily give, but I will breakdown the process and some of the scale.
Setting aside distribution which is a common problem between illegal and legal streaming. Production for legal streaming costs thousands of dollars per hour just to create the feed. A dozen cameras at the stadium, with camera operators pointing them. Vision directors, audio folk, production folk and a multi-million dollar truck or three to run the production from.
You're talking about fibre links around the world to move the media from the stadium to the transmission facilities. Playout systems to add extra polish to the look and feel (otherwise half-time would look rough), folks doing commentary (either at the stadium or remotely). Further fibre links to the cloud, Encoders, packagers and caches.
Almost every piece of equipment or software, is run in duplicate or triplicate to ensure that it's insanely reliable. There's not one fibre, but four, linking our two transmission data centres to the cloud. People don't expect much from a pirate site, but they'll threaten your life if you break the stream of their favourite sports team.
The pirates subscribe to us for just a normal consumer subscription and then rip off our content. They either use trial accounts or buy some credit on a public cloud under an assumed name. Sometimes they operate from compliant cloud providers who likely know what they're involved in (usually in countries with lax legal enforcement routes). The feeds themselves are usually separate as a business from the websites. The content acquisition is one activity, the hosting of streams is another and the hosting of the linking websites is another. On the black market pirates can get access to the source streams at some level or another and host them on a website. There is a mesh of money changing hands for access to content (sidenote: yes, crypto currency transactions are traceable to an extent).
Most sites are funded by advertising and link referrals, it's pretty old school. Some sites operate as closed paywalls which you need to get into by talking to the operator over Telegram and other sites. Those sites are slightly harder to track, but people like to brag about their favourite sites for watching on, so anti-piracy intelligence companies track those discussions.
Folk who share content on social media for their friends? We don't greatly care about them. But it still gets enforced because YouTube and the other social media sites aid us with Content ID matching, because if we didn't then people would use that and get that monetised at scale. Plus account sharing is still revenue loss.
As for whose doing this and why? The biggest operations are run through criminal rings, this is an organised crime issue. But it's also mixed in with a good number of ambitious and smart individuals who want to make a buck. Because companies crack down on it, there is a degree of money laundering and other financial crimes on top. One of the interesting things is how many of the apps used for piracy are also loaded with malware, which can be productive for these gangs in many other ways. LTT did a video about this recently which is worth a watch.
I'm doing a great deal of work at the moment which will increase the security of streaming, not because I want to screw over the consumers, but because I want to protect our efforts. Security and anti-piracy are just a small aspect of the effort we make, and it's all about protecting what we've got. I will also say, one big aspect of anti-piracy is that you don't want to look like a leaky ship to the rightsholder and to the competition. You don't want your competition to point at you and say "Bob's product is a liability, the rightsholder should give the rights to us." and you want the rightsholders to think you're the best place for their content. As a rightsholder, it's not just about protecting revenues, it's also about protecting the brand. Have you seen these pirate sites? They're junk and advertising all sorts of weird scammy crap. It's not a good look for them to have their content on there.
