Twitter collects
personally identifiable information about its users and shares it with third parties. Twitter considers that information an asset, and reserves the right to sell it if the company changes hands.
[21]
A security vulnerability was reported on April 7 2007 by Nitesh Dhanjani & Rujith. The problem was due to Twitter's using the SMS message originator as the authentication of the user's account. Nitesh used
fakemytext.com to
spoof a text message, whereupon Twitter posted the message on the victim's page. This vulnerability can only be used if the victim's phone number is known.
[22] Twitter introduced an optional PIN that its users can specify to authenticate SMS-originating messages within a few weeks of this discovery.
The site Qwitter
[1] was created to notify users when someone who was following them has stopped.
[23]
On January 5 2009, 33 high-profile Twitter accounts were compromised, and falsified messages—including sexually explicit and drug-related messages—were sent.
[24][25] The accounts were compromised after a Twitter administrator's password was guessed via a dictionary attack
