You have decided to join the Google+ community and are getting notifications of people adding you to their circles and requesting to be added back. You are flattered that these people seem to come from all over the world. But a simple check will show something very interesting. These people do not seem to have many people who have them in their circles. In fact, they have chosen you to be one of the first people that they subscribe to. In addition, their posts seem to tend towards pictures of themselves and other websites that have a common theme and that common theme is a little disturbing.
The truth is, these people do not exist. They are fabrications of commercial enterprises selling undesirable products or promoting radical causes. If you add them back into your circles, you may just have found that you are adding in a front for a terrorist organization or a pornographic website. There is a simple solution, examine the feed before you add them to your circles. If by chance they have been added by mistake, take them out of your circles. As genealogists, we do not need this kind of garbage and spam.