"New things are always happening here at Twitter HQ," the e-mail says. "We're growing at a rapid pace, and our commitment to simplicity, transparency, and reaching every person on the planet continues."

In the service's , it's offering more detail -- in plain English -- about what information it collects.  Not only does it collect information when you register with Twitter, but also profile information you post to your account.

"Our Services are primarily designed to help you share information with the world," Twitter explains. "Most of the information you provide us is information you are asking us to make public. This includes not only the messages you Tweet and the metadata provided with Tweets, such as when you Tweeted, but also the lists you create, the people you follow, the Tweets you mark as favorites or Retweet, and many other bits of information that result from your use of the Services."

Twitter also collects "log" information about you when you use the service or its widgets. That includes your IP address, browser type, operating system, referring web page, pages visited, location, your mobile carrier, device and application IDs, search terms, and cookie information.

Log information is purged after 18 months of collection, Twitter says; and after a maximum of ten days, Twitter will start to delete or aggregate your widget data, a process that's usually instantaneous, but can take up to a week.