Robert Scoble Has Too Many Friends

Robert Scoble is bragging about his Facebook friends. Apparently he has over 4,600 friends as of now. I have a tenth of that and have enough trouble keeping in touch with them. I wonder how many friends actually message him. I tried messaging Scoble the other day but got no response. He must have some effective filtering methods just as he does for reading his 2,000 blogs posts a day. How many friends is too many friends? How many friends do you have? I remember reading somewhere that you should be particular with the friends that you add on Facebook.