[anakha]

Using one of these in a public place will be an invitation to get mugged.

[mdonahoe]

I'm guessing this would get used in very loud public places, like airports or train stations. I'm also guessing that muggings would be rare because of all the bystanders.

However, wearing one of these in public is an invitation to get your picture taken and posted on twitter.

[skeletonjelly]

I think airports and university libraries are their big markets. Public space would be off limits in my opinion.

[Trufa]

You're already sleeping so mugging must be out before, pillow or no pillow.