What are These Strange Facebook Notifications?

[ambrella]

I have the Droid M Razor with Verizon and once every two or three days, I get a notification from facebook.

It'll state something like: "Tom Jones (Friends with Fred Smith)...". I can't see what the entire notification is because there are only a certain amount of characters allowed on the notification screen. But always, it is a friend of a friend, but never someone I know directly and am friends with on Facebook.

When I click on the notification it will take me to the Facebook app and an error notification will pop up, reading something like: "This page cannot be accessed. This may be due to a broken link, a removed link, etc." Basically, the error message is saying that I can't access the notification because the root of it is not found.

I always look at the person's page that had caused the notification to come up and they do exist. My assumption is that they look at my profile, and I am getting some sort of secret notification of it, but when I try to access it, Facebook realizes that I shouldn't be able to see that information.

Any ideas? It's not so much creepy or inconvenient as interesting; I'd just like to know why. If it happens again, I'll link to a screenshot of notification and error message. Thanks!!