Paying in cash is the first step, not the last. If the shop enters my vin into an online service to get the mechanic's manual for the VX, now that online service knows that I did business with that shop on such-and-such date. Paying in cash doesn't mitigate that.

And it isn't about being less of a 'target' than the next guy. I'm not trying to protect myself from being mugged. Big Data surveillance is a constant persistent threat that applies to everyone equally because its all computerized. The computers don't pick and choose, they log everything and keep it forever. It all goes into your permanent record. So even if they haven't figured out how to exploit the data today, they are always looking for new ways to use it in the future to make moar profits.

It is deeply scary to face the implications of all this, I understand why most people do not want to look too closely. Especially given how convenient life gets when you give away your privacy and there is never an immediate and obvious downside either.

But unlike old-timey kook conspiracy theories, this stuff is not hypothetical. Facebook has a market value of $500 billion when their sole source of revenue is monetizing people's private information and there are hundreds more smaller, even less scrupulous companies doing the same that you've never heard of (BlueKai, Acxiom, Choicepoint, etc). What's deeply troubling for someone like me, who has kept his nose squeeky clean his entire life, is not that they might correctly profile me, is that they get it drastically wrong because their algorithms are imperfect and I have no recourse. If you've seen the movie Brazil, think of the comically tragic Buttle/Tuttle mix-up.

So, my solution is to stay out of their systems as much as possible, to leave as few digital footprints as I can. Its the only thing a regular joe can do.