If you do a Google News search right now (it may be different when you read this, of course) for "Turbo Tax Security" you'll find a bunch of stories like this one: Glitch Gives Woman Access To Others' Turbo Tax Information.
If you were a Turbo Tax Online customer and this made you nervous (as it should), and you went to their web site right now, here's what you'd find on their home page about the incident:
If you looked farther down the news search results, you'd find out that they fixed it. But if you didn't look harder (and most people won't) but instead just turned to the company for an explanation... you'd probably wind up choosing a different tax prep option.
Information travels fast. Hiding doesn't work.