Twitter Social Graph 2009

Results of a full crawl of the entire Twitter site. 41.7 million user profiles, 1.47 billion social relations, 4,262 trending topics, and 106 million tweets.

This data was collected for the paper, What is Twitter, a Social Network or a News Media? by Haewoon Kwak, Changhyun Lee, Hosung Park, and Sue Moon.

A detailed descriptions of the datasets included fields can be found on the source website.

Openness

No license is specified but the dataset if clearly intended to be reused. However, the exact status of scraped data, especially from a source like twitter is unclear.