Mark Zuckerberg
Facebook Inc. CEO Mark Zuckerberg, 27, will control nearly 60 percent of its stock once the company goes public. Reuters

Facebook Inc. registered its initial public offering with U.S. regulators on Feb. 1 but has amended it twice, most recently on March 8.

There's little reason to suspect the U.S. Securities and Exchange Commission would hold up the IPO, but given the buoyancy of financial markets, one can imagine that Facebook Chief Executive Mark Zuckerberg is just waiting to cash in.

The original registration document provided the first glimpse of the company's financials. Prospective investors learned that Facebook has 845 million daily users and last year's net income totaled $1 billion on a surprisingly small $3.7 billion in revenue. Most revenue came from advertising, along with some from gaming via partner Zynga Inc. (Nasdaq: ZNGA).

Here's what's new in the latest amended filing:

Facebook now has a credit line of $5 billion, double its previous line. The company didn't disclose what It needs the money for, just as it previously disclosed it didn't need to raise cash in the IPO for any other reason than to enable Zuckerberg, 27, to pay capital-gains taxes. He'll control nearly 60 percent of the equity.

Still, whenever it goes public, Facebook may have a market value of $100 billion or more, plus the cash that could be used for acquisitions. Beefing up the credit line also gave it more banks to tap because the funds came from 31 in all.

Facebook also added an extra $3 billion in a new bridge loan. Funds came from J.P. Morgan Chase & Co. and Morgan Stanley. That money will be used to pay off employees who were vested with stock before the IPO.

Facebook now has more underwriters. While it may not mean much to investors, sweetening the underwriting pie assures more Wall Street interest.

The company added Citigroup Inc., RBC Capital Markets, Credit Suisse, Deutsche Bank Securities and Lazard to its previous list of underwriters -- J.P. Morgan Chase, Goldman Sachs Group Inc., Morgan Stanley and Allen & Co.

More fees are to be had, so whenever the SEC approves the offering, a big reception is guaranteed.

Facebook has been sued for patent infringement. The threat of a lawsuit by Yahoo Inc. (Nasdaq: YHOO) was cited in the latest filing but on Monday, it turned real. Yahoo, holder of 1,029 patents, sued in U.S. District Court in San Jose, Calif., accusing Facebook of infringing on at least 10.

Facebook, holder of only 56 patents with another 104 pending, issued a statement but has not yet filed a countersuit.

"This is a great opportunity" for new Yahoo CEO Scott Thompson, said Lance Lieberman of Cozen O'Connor, a New York intellectual-property lawyer. "Facebook is in a really tight spot."

Lieberman, who isn't involved in the case, suggested Yahoo chose the right time to sue Facebook, given the breakdown of prior negotiations. He suggested Facebook may well settle for cash or shares in the IPO, acknowledging Yahoo's claims.

Indeed, the lawyer suggested that Yahoo, with a deeper portfolio and longer heritage than new social media companies, may well be starting a new chapter to collect royalties for IP it invented years ago.

Perhaps to irritate Facebook's Zuckerberg, Yahoo hired the same law firm that handled the claims of Tyler and Cameron Winkelvoss that their ideas about a social network site were appropriated by their former Harvard classmate.

The Winkelvoss twins are no longer Facebook shareholders, the prospectus says. Their settlement with the company has been sealed.

For the record, the law firm is Quinn Emanuel Urquhart & Sullivan of Los Angeles.

Facebook acknowledges it has fake accounts. Not unexpectedly, in a universe of 845 million users, some have to be phony. In the latest filing, the company estimated as many as 6 percent are fakes, which translates to 50.7 million.

That's important to Internet advertisers seeking to reach eyeballs, as well as investors who might want to calculate how much revenue is generated per user.