First, by using Twitter's service, I consent to the collection and use of my personal information including usernames, passwords, and email addresses. Email addresses may be used to be sent information deemed important by Twitter, or marketing material.
Another blurb in the privacy policy reminds me that my tweets are public and can be searched via search engines. The same blurb says that my tweets can be disseminated via text message or API to a "wide range of users and services." It makes no specific mention of which users or what services.
Apparently Twitter also saves my location information if I choose to share my location. They claim this information helps them serve me better.
Other information saved by Twitter can include my IP address, browser type, pages visited, cell phone carrier, and device. The policy says that this information may be deleted every eighteen months.
The policy states again that Twitter reserves the right to share information with certain third parties, but again makes no specific mention of who the third parties are or the reason the information is sent.
Finally, it says my information may be sold if Twitter is sold, merges, or files bankruptcy.
Disturbingly, neither the TOS or privacy policy makes mention of what would happen in the event of a security breach, only that I can't use Twitter to cause one. Thanks, Twitter.