A few years ago, I was at a party at a conference and found myself chatting with a reporter for another liberal magazine. We talked for a while about politics and the media and then went on to other conversations. About a week later, something I said during that conversation ended up in a story she wrote. She quoted me accurately, and it wasn't anything particularly shocking, but I was still surprised and a little insulted that what I had assumed was just a friendly conversation was actually a secret interview, with her taking feverish mental notes. But she was playing well within the rules everyone who deals with the press understands: When there's a reporter in earshot, you should just assume that whatever you're saying is on the record and may be quoted.
Savvy politicos make sure their bosses know what the current price of items like milk and gas are, because every once in a while someone will deliver a little pop quiz to the candidate, and the last thing a politician wants is to appear "out of touch" with ordinary people, like the kind of guy who doesn't buy his own groceries. I've always thought those kind of quizzes are silly -- in my experience, ideology has a lot more to do with the priorities politicians have than how "in touch" they are. It's not like you're going to find too many Republicans saying, "I had no idea it was hard to make a living on $5 an hour -- from now on, I will support increasing the minimum wage!"