Not only is this not surprising, it’s arguably warranted, given what has been revealed in the days after the world’s largest IPO turned into the largest IPO faceplant in recent memory. Three investors have filed lawsuits against Morgan Stanley and Goldman Sachs after revelations that it revised its revenue forecasts on Facebook just before taking the company public — without notifying the investors they sought to attract:

Three Facebook Inc. investors filed a civil lawsuit Wednesday in Manhattan federal court, alleging the company and its underwriters failed to properly disclose changes to analysts’ forecasts made at the underwriting banks.

The suit follows reports that analysts at Morgan Stanley and Goldman Sachs Group Inc. cut their revenue forecasts on Facebook amid the investor roadshow, a change that wasn’t widely disseminated.

Late Tuesday, Massachusetts sent a subpoena to Morgan Stanley following the reports. Several other plaintiffs’ lawyers have said they filed suits over the offering in other courts throughout the country, seeking class-action status.

Wednesday’s investor suit, which also is seeking class-action status, alleges the changes made to Facebook’s offering document, which said that mobile-user growth could slow revenue growth, didn’t accurately portray the impact on Facebook’s revenue growth.

The entire mess could have been avoided, the Wall Street Journal also reports, had the CFO of Facebook had not expanded the offering, which arguably diluted the value of the shares:

Less than three days before Facebook Inc.’s initial public offering, Chief Financial Officer David Ebersman decided to boost the number of shares the company would offer investors by 25%, said people familiar with the planning. His main adviser at lead underwriter Morgan Stanley assured him there was plenty of demand, they said.

That decision by the 41-year-old Facebook executive may have doomed any real chance the social-networking company had that its stock would jump on its first day of trading—a hallmark of successful IPOs. On Tuesday, the second full day of trading, Facebook shares fell $3.03, or 8.9%, to $31, after falling 11% on Monday. Investors are blaming the downdraft on the last-moment expansion of the offering.

Securities and Exchange Commission Chairman Mary Schapiro said Tuesday that her agency will examine “issues” surrounding the IPO in an effort to ensure confidence in public markets. An SEC spokesman declined to elaborate.

NASDAQ now says that they would not have allowed the IPO to take place had they known of the technical issues in the offering.  Wall Street watchdog Financial Industry Regulatory Authority has also pledged to investigated allegations that both underwriters unfairly warned select groups of investors about problems in Facebook’s ad-sales growth.  Put it all together and it looks like a viable basis for a class-action lawsuit that might end up getting “friended” — or at least “liked” — by millions of investors.

On the other hand, WSJ’s NewsHub says investors should have been well aware of Facebook’s limitations:

“When the insiders are selling …” This is a very good point, and a reservation I’ve had about this as a casual observer from the beginning.  Some companies go public to get cash for major expansion or acquisition strategies.  In this case, though, it looked more like Facebook’s top cadre wanted to cash out.  There’s nothing inherently wrong with that, but it suggests that the company won’t get much more valuable than it is at the moment it goes public, at least not for a long while.

None of this is a problem for long-term investors who want to remain a part of Facebook for reasons other than short-term profit.  But clearly, Facebook and its underwriters have botched their launch as a publicly-traded company, and it will take a long time to rebuild the credibility lost this month.