Can one WordPress install handle at least 100,000 user profile pages (5m visitors a month), 20-100 pictures per profile, taging, facebook-like wall, private messaging system etc.?
What's the limit with WordPress? When thigs will get really slow?
The biggest sites I've seen so far are Envato's marketplaces like ThemeForest but content there is added by editors, mostly.
Do you have any examples of such sites?