A reader writes:

"I've had an interesting experience with two "friends" on facebook. The first was about 6 months ago, with an old friend who I never talk to from about 20 years ago. After I friended him, I started to get movie reviews all the time from him ---about three a day, but only on my iPhone, never when I actually logged in on a regular computer. I never got a personal message from him, and he never posted anything that looked truly personal except a few photos. Here is the tricky thing about the iPhone app. You can't manage your friends on it. But then when you go online with a regular computer, none of his posts are there, so you forget you want to delete him. Eventually, I did delete him.

Then just a few weeks ago, another "old friend" who I didn't recognize, but who my other friends gave testimonials about remembering them from high school (20 years ago), convinced me to friend this person. Once this happened, I would once again get lots of stuff on my iPhone mobile app, but little on my regular computer. This time it was from the facebook games. I don't even remember which ones anymore. One thing about this person was really odd. She posted a couple of things that appeared to be normal personal posts, and in reply, she would get 2,500 comments in about 1 hour.

Something strange is going on. It's like facebook is selling special privileges to some companies so that they can do some odd marketing through the mobile app."