While Twitter maintains that its servers have not been hacked, the company now says it has "cross-checked" the account data noted by LeakedSource and is taking pre-emptive measures. Particularly notable in light of hacks that have recently affected accounts from Katy Perry to Mark Zuckerberg to the NFL, the social network said it has identified a number of accounts for extra protection. No matter where the information came from, whether via malware or shared passwords revealed in hacks of other services, any accounts with "direct password exposure" have been locked (similar to pre-emptive moves Netflix and others are using when they see account details floating around), and emails were sent to the owner prompting for a password reset.