https://www.theverge.com/2017/9/26/16367620/showtime-cpu-cryptocurrency-monero-coinhive

This past weekend, Showtime websites were found to be running a script that allows the sites to mine visitors’ extra CPU power for cryptocurrency, as pointed out by users on Twitter. The afflicted sites included showtime.com and showtimeanytime.com, but the script has since been removed following reports from Gizmodo and other sites.

The crypto mining Javascript is called Coinhive, and according to the site, it was made as an alternative to banner ads as a way for website owners to get around pesky ad-blockers. Ironically, some ad-blockers have now included Coinhive on the list of the banned.