Twitter recently rolled out support for two-factor authentication to bolster the security of its user base. The company made the move following the announcement of a data breach in February that exposed the usernames, email addresses and encrypted passwords of 250,000 users. The company announced that it detected unusual network activity. "We discovered one live attack and were able to shut it down in process moments later. However, our investigation has thus far indicated that the attackers may have had access to limited user information," wrote Bob Lord, director of information security at Twitter. "This attack was not the work of amateurs, and we do not believe it was an isolated incident."