Google made its new social network, Google +, open to all users for a couple hours before it was overwhelmed by early adopters. (HO/REUTERS)

But at around 8 p.m. or so Wednesday, the service let any user on the network send invitations to any of their contacts.

As tweets about invites exploded, so many eager early adopters flooded the network that Google had to step back into its closed field tests.

“We've shut down invite mechanism for the night,” wrote Google social head Vic Gundortra a few hours later on Google +. “Insane demand. We need to do this carefully, and in a controlled way. Thank you all for your interest!”

Google’s been criticized for the way it’s rolling out +, a complaint that it’s faced with almost all of its new services. But by sticking to a closed beta like it did with Google Wave, the company runs the risk of killing an innovative product by not letting enough people play around with its features.

I’m still gathering my thoughts for a review to come later today, so check back here for my take and join us for a chat about Google + at 12:30 p.m.

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