Dunbar's number is 150.
And he's not compromising, no matter how much you whine about it.
Dunbar postulated that the typical human being can only have 150 friends. One hundred fifty people in the tribe. After that, we just aren't cognitively organized to handle and track new people easily. That's why, without external forces, human tribes tend to split in two after they reach this size. It's why WL Gore limits the size of their offices to 150 (when they grow, they build a whole new building).
Facebook and Twitter and blogs fly in the face of Dunbar's number. They put hundreds or thousands of friendlies in front of us, people we would have lost touch with (why? because of Dunbar!) except that they keep digitally reappearing.
Reunions are a great example of Dunbar's number at work. You might like a dozen people you meet at that reunion, but you can't keep up, because you're full.
Some people online are trying to flout Dunbar's number, to become connected and actual friends with tens of thousands of people at once. And guess what? It doesn't scale. You might be able to stretch to 200 or 400, but no, you can't effectively engage at a tribal level with a thousand people. You get the politician's glassy-eyed gaze or the celebrity's empty stare. And then the nature of the relationship is changed.
I can tell when this happens. I'm guessing you can too.