One of the websites had been streaming movies since 2013, and there were more than 2,500 films on the website, including flicks in the Latvian language. An anti-piracy agency contacted the copyright holders who then turned to the police.
It is estimated about 27,000 people visited the aforementioned website each day, with 71% of the visits coming from Latvia.
Investigators say the websites sold advertising space, and used schemes to hide the true owners of the websites.
Piracy is a serious offense that carries a prison sentence of up to six years in Latvia.
Police searched locations in Rīga and Liepāja, seizing data carriers and bookkeeping documents.
According to the MUSO anti-piracy analytics website, in 2016, a whopping 46.3% of Latvians used the web to access illegal content, followed by Bulgaria (27.4%) and Lithuania (24.5%).