More difficult on the receiving side.
It’s nice for those concerned about privacy that their profile is set to limited by default.
But there seems to be an inconvenient side effect from it when receiving invitation. When getting an invitation, my first rule of thumb is to check their profile and see how active they are. Space hasn’t been so popular so there’s another way in assessing their activity by web activities. If the activities are empty, or only filled with so many contact adding without any sharing, that means reject the invitation.
The new privacy option hide all those to strangers. For peoples invited, there’s no difference between profile of someone who’s activity hidden behind privacy wall, and a dead profile without any activities, all empty.
There’s a simple way to balance it though, like used in Twitter and FriendFeed. In the invite mail, include some of the latest activities from the person, so we can see if that person is active or just in a contact adding frenzy. Leaking privacy? Well, if that person is sending invites to join his network, he should be ready to share it with the person he invites anyway, so I don’t think there’s something wrong with it.