Yep. I was part of the Web Ecology Project in 2009-2010 and we were able to get pretty awesome access to Twitter at the time. I had a good dialog on a weekly basis it seemed with their API team and they were super responsive and supportive of us. Although, whenever I asked what we needed to pay for full Firehose (which some companies were getting) I couldn't get an answer from them, and I think they only wanted to talk with huge companies.

Then that all stopped. No more whitelisted IPs for search, no more new whitelisted accounts for API calls, and then they stripped all my whitelisted accounts of their 20k/hr API calls and put them all back at the standard 150/hr or whatever.

And what's worse is the network is bigger than ever. Instead of scaling API access up with network size, they scaled it down. This is really a shame as I think Twitter is terribly interesting to with it from an academic standpoint, but unless you have huge money to shell out for API calls or direct access you're screwed.