Although it hasn't gone to the Justice Department, and although the SEC has (I hope) at least given it a once-over (though that's not entirely clear), Microsoft and other high-tech companies' stock option schemes can be argued as allowing them to misstate financial information (eg, liability for said options) pretty badly.
I seem to remember the SEC telling Microsoft to quit cooking their books to even out revenues between financial quarters. Microsoft in effect said "We'd never do that, but if we did we won't do it again."
That's only two examples of bookkeeping irregularities, but the book-cooking (or as I believe User Friendly put it, Martha Steward's Guide to Book Sauteeing) is a sign that they certainly aren't very interested in being open and honest about their revenues, assets, and liabilities. And where there are a couple of irregularities, there could certainly be more if you start digging deep enough. And once you start digging, you never really know what you'll find.
Informix, once *the* leader in relational databases but long ago surpassed by Oracle, stayed alive for quite some time but was eventually put to rest by the discovery of a series of increasingly bad financial irregularities (misstating inventory, booking sales when things hadn't actually been sold, stuff like that - I forget exactly all of what they did, but it was news at the time) which certainly *appear* to have been designed to make their finances look better. Not nearly as bad as the phoney holding/trading companies Enron set up, but bad enough... hmmmm, beginning to sound a little like manipulation similar to Microsoft.