I can confirm this bug. A few months back my company macbook started freezing up multiple times a day. I could see from the activity monitor that disk access stopped completely. The SMART status was OK, and all sorts of other disk tools could not find a problem. The drive is a Crucial M4 256 GB. After a few weeks of these random failures I realized they seemed to happen pretty consistently every hour, and eventually I found out about this firmware bug. After doing some calculations, the "5184 hours of Power-on time" matched up very nicely with the date I started using the drive and the almost 24/7 power-on time (I just leave it powered on at my desk). So I installed the firmware upgrade and the problem went away. It's a pretty crazy bug - there must be many thousands of these drives out there just waiting to hit this magic power-on time and start failing. How many of those users are going to know about the firmware update?

I don't know much about this stuff, but isn't it possible to analyze the entropy of the hard drive data to find areas that contain encrypted data?

I remember a while back reading about ways to scan a program's memory looking for encryption keys and encrypted data because that data is much more random (or seemingly random) than the surrounding data.

Surely this would also apply to a hard drive? Imagine amongst all the old text files, images, documents, there is suddenly a huge 1GB area of totally random data. That's got to raise suspicions.