More and more people are beginning to watch TV series and although we just watched them in their normal quality (or even in the 720p form), now with TVs and monitors supporting 4K resolution this will change quickly. So pirates give us the opportunity to watch our favorite TV series in 4K resolution, enjoying the most of these new devices.
Though 4K devices are not yet a trend, it will slowly change, while you are also seeing the stuff that pirates upload, where more and more files are going up high resolutions. According to torrentfreak, pirates found a way allowing them to copy movies and TV shows in 4K resolution from Netflix and Amazon. So the High-Bandwidth Digital Copy Protection (HDCP) system "cracked" and is available to the public.
The first TV shows that uploaded to 4K are The Man in the High Castle and Jessica Jones, although the files are too big (exceeding 10gb many times).