The Office of the United States Trade Representative (USTR) says that pirate sites are making a fortune through advertising, and has highlighted the increasing use of illicit streaming devices in a new report.

The Notorious Markets List 2017 describes the growth in such devices as 'a troubling threat to the pay TV and other content industries' that 'undermines incentives for companies to improve services or offer a greater selection of content in more markets'.

Between them, it claims, unlawful device sellers and unlicensed video providers and video hosts are raking in as much as $840 million a year in North America alone, costing the entertainment industry $4-5 billion a year.

However, the report notes some successes over the last year, most notably the prosecution of Sharebeast for the illegal distribution of copyrighted music and albums on a massive scale.

More recently, youtube-mp3.org, an unauthorized stream ripping site called out in last year's report, shut down as a result of a civil action and other sites have reportedly stopped promoting or allowing unauthorized audio ripping from music videos and legitimate streaming services.

But, says the report, "Though circumstances exist where stream ripping could be lawful, such as if the content were licensed for that purpose and the conversion were permitted under the legitimate service’s terms of use, the operations of many unauthorized stream ripping sites reportedly continue to contribute overwhelmingly to copyright infringement."

Advertising on piracy sites remains a big problem. According to an independent review of the top 5,000 IP-infringing URLs in the US, the EU and Australia, as much as 25% to 30% of advertising on websites posing an IP risk comes from major brands. The fastest-growing ad network amongst infringing sites is WWWPromoter, based in Canada.