Twitter API stops accepting whitelisting applications
groups.google.com
groups.google.com
The biggest difficulty with twitter is that there is no way to get the social network, and the REST API was the only way of getting it.
Thus any deep social network based analytics are difficult to perform.
Dear Developers, we’re cutting you out now that we think the value of our company is in the aggregate data.
A good thing about twitter was that their social network was more open than the facebook's social network, with newer rate limits its going to be really difficult to crawl it.