The net-net is _never_ give your credit card to anyone who suggests they will charge you, unless you have full control over that relationship.
It's the key reason why I subscribe to all my magazines and newspapers (key exception being the WSJ) through iTunes - single place to control subscriptions - with the added bonus that I get reminded every month that there will be a renewal coming up.
I also negotiated with my Gym to allow me to pay the full year up front + initiation fee to avoid having to give them my credit card - It was amazing how difficult it was for me to convince them to allow me to give them $410 up front for a $30/month gym membership. They really make a lot of money off of people who don't want to come into the gym and cancel, or forget to do so on their "Annual" anniversary when they get signed up for another year.
Most of us are in our early 20s when we discover the downsides of recurring credit card charges - I'm surprised that someone as savvy as Arrington is discovering that he can't just cancel his account to end those recurring charges - I thought it was something that students usually do and discover doesn't work. I certainly did when I was a student.