You've probably never heard of Manwin or Fabian Thylmann, but chances are good you've spent some quality time with their products. Manwin is a multimillion-dollar, international porn giant that owns more than 35 properties, including popular brands like YouPorn, PornHub and Brazzers. Now its owner, who has built a reputation as a skilled, ruthless businessman has been arrested in Belgium under suspicion of tax evasion.

The man CNBC has called "The new king of porn," Manwin's 34-year-old German managing partner Fabian Thylmann, was arrested at the Brussels airport today, according to trade magazine Xbiz. Manwin has slowly amassed an unprecedented holding of companies by taking a technology- driven approach to the porn industry, especially through its empire of free "tube" sites, like YouPorn.

Thylmann has aimed to be a different type of porn kingpin, playing up the high-tech aspect of Manwin instead of the sex parts. He's earned an image as a sort of Mark Zuckerberg of porn, even convincing a Wall Street investment bank to give him a nine-figure loan in 2011. Manwin's YouPorn and PornHub boasted 5.5 billion page views in July, compared to Wikipedia's 6.3 billion, according to Germany's Bild newspaper. More recently, Manwin has spearheaded an effort to stop the the new .XXX domain for porn sites. Manwin sued those administrating the new domain, arguing they're monopolistic and are attempting to extort existing porn businesses.

But today's arrest suggests there's more to Manwin than its technological innovation and industry leadership. The news of Thylmann's arrest shook insiders among southern California's porn industry this morning, where Manwin wields huge influence but has also been viewed with increasing suspicion as its dominance has grown. Manwin keeps its operations under tight wraps, and some in Porn Valley see the arrest as the start of a long unravelling. Mike South, the irascible porn gossip blogger who has made a career out of needling Manwin, is predictably gloating today. He wrote:

Many is the time I told Fabian I would live to see him taken away in handcuffs…..The good is I did, the bad is it isn't for what he should have been arrested for, the good is it's likely just the beginning. Whose laughing now Fabian?

Manwin did not immediately respond to a request for comment.