Leonid Radvinsky is hardly a household name. After buying OnlyFans in 2018, the Ukrainian-American businessman stepped out of the shadows of the porn industry.

In 2016, Tim Stokely founded the subscription-based adult-content platform before Radvinsky took over.

The investment appears to have been successful. The platform’s annual report states that its user base more than doubled to 188 million during the pandemic. Platform revenue is 20%, and Radvinsky has earned over $500 million since 2020.

In the world of adult content, OnlyFans is not his first venture. At 17, he founded a company called Cybertania in Chicago after moving with his family from Ukraine. During the early 2000s, Forbes reported that the company marketed “hacked” and “illegal” passwords for porn sites last year.

Password Universe, on one of the websites, featured a link to a site that advertised tens of thousands of “illegal preteen passwords.” Forbes reported that Ultra Passwords linked to “the hottest bestiality site on the internet.”

Forbes found no evidence that the sites linked to an illegal content, but the affiliate links seemed to be a way to generate revenue.

As his next venture, Radvinsky set up MyFreeCams, a webcam porn site where “models” performed sexual acts. According to the adult industry news site XBiz, his site had more than 100,000 models and five million members by 2010.

He built his empire by acquiring other porn-related domain names, such as ultraxxxpasswords.com, after graduating from Northwestern University in 2002 with a degree in economics.

In the 2000s, forensic journalism site Forensic News reported, Ultra Passwords pulled in $1.8 million a year in revenue from its online “bulletin board” of passwords for adult sites.

Radvinsky continued to purchase porn-related domain names. According to domain-name records, he owned at least 950 domains, including sexhackers.com and camwhores.com.

Forbes estimated his net worth at $1.2 billion as of April, with assets including a Florida mansion and a Chicago penthouse.

Besides what he has disclosed on his website, Radvinsky has little information about his personal life or activities. As well as supporting open-source software, he invests in philanthropies.

The billionaire donated $5 million to Ukraine relief efforts earlier this year and cancer charities, animal welfare organizations, and skin-disorder research organizations.

As well as investing in B4X, he has backed Pleroma, a social network software company. Radvinsky invests up to $1 million in company founders through his venture-capital fund, Leo.

A helicopter pilot is also on Radvinsky’s bucket list. As part of the Vertiport team in downtown Chicago, he has 95 flight hours.

In the meantime, he hopes to become wealthy enough to “one day be able to sign The Giving Pledge.” Bill Gates, Warren Buffett, and MacKenzie Scott are among the billionaires who have pledged to donate most of their fortunes to charitable causes.

Over the years, Radvinsky has had a few legal headaches in adult entertainment.

His first company, Cybertania, was sued by Microsoft in 2004 for allegedly sending “millions” of illegal and misleading emails to Hotmail users.

Forbes reported that Radvinsky denied the allegations and said that the case was settled out of court after emails were “falsely labelled” as being sent by Amazon.

BBC News reported that OnlyFans creators sued Radvinsky and Meta in February, alleging that he bribed Meta executives to blacklist content creators who worked with rivals. As a spokesperson told the BBC at the time, the claims had no merit, and Meta denied them.

Based on anonymous sources and emails, OnlyFans’ lawyers argued that the lawsuit lacked a “reasonable evidentiary basis” in October. There is still a case pending.