That's just javascript minimization. Standard way of reducing page load times. It's been around way longer than Google Closure, just look at YUI Compressor. It

That's just javascript minimization. Standard way of reducing page load times. It's been around way longer than Google Closure, just look at YUI Compressor. It may stop anyone from looking at a page's source code, but I'd think most developers would put greatly reducing load times ahead of having your javascript being freely read.