It's not a secret, but I don't think we're doing enough to keep this on the forefront of people's minds. Every time I hear this, I am shocked! Only to then remember I already knew this but somehow let it slide...

I mean, what's the difference between this and customizing billboard ads based on where the billboard is?

IMO the issue is not google using IP-based location info. The issue (if there really is one) is people assuming/believing the internet hides their location.

hmm, that's a very interesting point. I guess that famous saying of "if you're not paying, then YOU are the product" kinda falls into play here, huh?