I don't recall anyone ever picking my friends for me. If i had friends my parents were suspicious of, they might tell me that but they never told me i wasn't allowed to be friends with anyone.
Likewise, my son has always chosen his own friends. Now, there have been one or two that i have said can't spend the night bc they're too hyper/obnoxious. When he gets to HS, i'll keep an eye on who he is hanging out with. If i really think someone is a bad influence or a bad kud, i'll tell him what i think. The kid would have to be up to no good/criminal/dangerous/using drugs for me to ban him as a friend. I guess we'll see how it all pans out