Privacy?

I sent a note to my kids yesterday:

So I figured out something I could use: headphones preloaded with an endless supply of music so I don't have to listen to the sports announcer's yammering while I am watching a game.

This morning I'm surfing the net, reading about the nuclear power industry in the Northwest, and ads for headphones start popping up. Google, you're reading my mail now? Dog-tards. Well, I guess I shouldn't really expect any privacy on a FREE service.