We are living in a golden age of illegal TV streaming - and it's putting a dent in pay-TV audiences

Something very sudden and very weird has happened to sport on TV in the last few weeks. Viewers stopped watching it:

• In the UK, the TV audience for Premier League games fell by 19% through early October.
• In the US, TV ratings for NFL games slipped by 10% over the first four weeks of the season.

Of course, the number of people paying for cable and satellite TV has been declining for years, according to data gathered by BI Intelligence. But that decline is slow, a few points per year. It's not a sudden drop of 10% or 20% annually.

On the other hand, a huge number of people are now watching illegal TV streams on the web, from sites like Putlocker, 123Movies, SportstreamTV, FirstRow, Rojadirecta, Live TV, Drakulastream, and Cricfree, and over devices like the Kodi Android box. It is not possible to say definitively, but it is possible that illegal TV streaming has become so widespread - and of such high quality - that it is, at last, putting a real dent in the traditional pay-TV business.

It is difficult to put numbers on how big illegal TV streaming has become - it's illegal, after all. But it is clearly huge. The BBC reported that some individual sites are publishing 8 million TV streams per month. The Daily Mail has reported that 1 million people per month are watching the Premier League illegally on streaming sites.

In the US, of those who watched the presidential debates online, 41% who watched did so on illegal streams, according to VFT Solutions, a company that protects media IP rights.

Those streams aren't grainy video boxes that stop and stutter, making them more trouble than they're worth. In a one month sample, Friend MTS found more than 12,000 unique HD channels (1280 x 720 pixels or greater) on pirate sites sourced from legit TV companies.

While conducting research for this article (ahem), your author watched the first three episodes of "Westworld" without paying HBO a penny. The quality was high-definition, crisp and clear, and the site that provided them had a few great user-experience functions, such as a favourites list, alerts for new episodes, and it automatically remembered where I left off watching so I could pick the show up again seamlessly.

Illegal sports streaming often isn't such high quality. It's not clear why sports sites offer their video at lower resolutions and cluttered with ads (many of which carry malware). Presumably, the logistics of providing an uninterrupted live feed of a match that will attract a sudden, massive demand from fans are more difficult than providing TV shows and movies, where demand is smoothed throughout the day.

But when a viewer is faced with a choice of expensive sports packages, then futzing with a fussy free site to watch a game seems like a relative bargain. At £42 a month for football on Sky TV, or $56 a month for the NFL on Comcast, it can cost you about £504/$672 just to follow your team for one season.

The sites play a constant cat-and-mouse game with the authorities trying to shut them down. As soon as one site is forced offline, a mirror of it appears elsewhere under a slightly different URL In January 2016, Wiziwig was forced offline. The site was massively popular with soccer fans. But within days similar destinations like Cricfree and SportstreamTV picked up where Wiziwig left off.

In 2014, the Premier League successfully blocked 45,000 illegal streams, according to Friend MTS, a video media rights security group. That hasn't reduced the number of free TV options online, however. And the ones that still exist - like 123Movies - are getting better at providing a quality experience. They are highly incentivised to do it, too. Between 2008 and 2013, a Northern Ireland man earned £300,000 running ads on an illegal TV streaming site before he was arrested and jailed.