Serious Tubes Networks is an internet service provider based in Stockholm, Sweden.

[1] The company was best known for providing network connectivity for the Pirate Party of Sweden and for hosting The Pirate Bay, a major BitTorrent search engine.

[2][3] In May 2011, the website of The Pirate Bay was unreachable to Comcast customers.

Serious Tubes Networks later announced that it was due to a routing configuration error at Global Crossing, which was providing service for Comcast.

[7] The site was offline from approximately August 2013[8] to September 2017,[9] after which the company seems to have been relaunched.