Exhibit B: The Apple Snow Leopard upgrade. Amazingly, some unlucky Mac users who access their systems using the "guest" login get a special treat: . (As the saying goes, that's no way to treat a guest.) Apple has acknowledged the problem, says only a small number of users have been affected, and is . If not for Microsoft's complete bungling of the Sidekick situation, Apple would be in the hot seat this week.

Exhibit C: For the past 10 days or so, Facebook has been grappling with a data loss problem of its own, which . About 0.05 percent of its users -- roughly 150,000 if Facebook's subscription numbers are to be believed -- had their personal profiles flushed down the technology toilet.

I've been in touch with a well-connected Cringester who lost close to 5,000 contacts in Facebook and was in the process of slowing rebuilding her friends list, one FBer at a time, when her account was finally restored. She received an e-mail that attributed the disappearing act to "an extended technical issue." Hmm, ya think so?

However, parties close to sources inside Facebook tell me the service was hacked. (If I can confirm that, or learn more about the actual cause, I'll let you know.)

If that's true, -- though it would be the first time so many user profiles were totally scotched. Still, regardless of the cause, it's troubling, especially because I don't know of any way to .