If you don't recognize the name, and you are uncomfortable with giving an unknown person such an "elevated" status (what the connection does, I'm not totally sure, even though I have a number of these digital-PB-pals myself)--then just ignore it. On the other hand, you (or the other) might try PMing, in order to get or give more info to help your decision.
I don't know about the list, or why a name is/isn't there. Sometimes the system lets people who are not "all-the-way-in" (someone waiting for membership) do certain things, probably because they have to have limited communication in order to request membership. I can't say for sure.