I've heard of bugs being spun as features before, but this takes the biscuit.

Although Glass might look like the ultimate X-ray specs for spying, Starner argues that Google has intentionally designed it to prevent snooping by limiting its battery life. Whereas your phone can surreptitiously record audio and video for extended periods of time, Glass will conk out after about 45 minutes (and get hot in the process). Starner insisted to conference-goers that this was a design feature meant to protect privacy, not a flaw.