PayPal billionaire Peter Thiel has donated an additional $1.7 million to a super PAC supporting Republican presidential candidate Ron Paul, making him the primary funder behind Endorse Liberty Inc. since it was founded late last year.

Federal Election Committee filings show Thiel, who Forbes estimates has a net worth of $1.5 billion, donated $1 million on Jan. 3. On Jan. 13, he donated another $700,000 to Endorse Liberty.

Thiel also gave the super PAC $150,000 on Dec. 16 last year and $750,000 on Dec. 21, bringing his total contributions to $2.6 million since Endorse Liberty was founded by three businessmen in December, according to The Center for Public Integrity, According to a Jan. 31 press release, Endorse Liberty raised a total of $3.9 million. The numbers show Thiel funded about 67 percent of the super PAC as of Jan. 31 (or 75 percent of funds raised in just the month of January).

That $2.6 million is hardly a dent in Thiel's pocket. The 45-year-old tycoon was among the first investors of Facebook, giving Harvard dropout Mark Zuckerberg a half-million-dollar loan in exchange for 7-percent ownership. If Facebook's IPO is valued at $100 billion, Thiel's 44 million shares could add up to $2.5 billion, The Huffington Post estimates. He is also the president of the hedge fund Clarium Capital and managing partner of venture-capital firm Founders Fund.

A self-described fairly staunch libertarian, Thiel told in 2007 he favors free-market economics and is liberal on most social issues. In a Daily Beast piece published on Feb. 12, he said Everything else is being regulated to death. He has invested in schemes to create libertarian islands in international waters. An out gay man, Thiel has also hosted a fundraiser for gay conservative GOProud at his New York City apartment in 2010.

His fellow PayPal co-founders Luke Nosek and Scott Banister also made smaller contributions to the Paul super PAC. Banister gave $50,000 in December while Nosek gave, $10,001 in January. Stephen Oskoui, a co-founder for Endorse Liberty and the founder of Internet advertising firm Smiley media, is another big donor.

Endorse Liberty has already spent more than it raised in January. Some $2.5 million of the $2.9 million raised went for online advertising on sites like Facebook, Google and The super PAC also has created parody videos of other presidential candidates, like a Fake Mitt Romney endorsing Ron Paul ahead of the Iowa caucuses.

Super PACs are new on the election scene this cycle and have proven to be the preferred method of donating money by big-time donors. A Pro-Romney super PAC, Restore Our Future, shelled out $14 million in January for the former Massachusetts governor, according to The New York Times. Only 37 people have contributed to more than half of itemized super PAC money, according to an analysis by PIRG and Demos (cited by