The email alert came as the company revealed more information about their internal investigation regarding Russia's role on Twitter during the 2016 presidential campaign.
While Russian officials have denied meddling in the 2016 presidential election, social media companies have discovered Russian-linked accounts that posted divisive content during the 2016 election season.
The social media giant said the Internet Research Agency, a Russian government-linked organization, was "connected to a propaganda effort" that included meddling in the 2016 US presidential election. "At the request of congressional investigators, we are also sharing those account handles with Congress". This is a continuation of the investigation that started previous year, and Twitter says that "through our supplemental analysis, we have identified 13,512 additional accounts, for a total of 50,258 automated accounts that we identified as Russian-linked and Tweeting election-related content during the election period".
Example of some of the IRA-bot-promoted content on Twitter. Twitter also shared a number of the tweets from IRA-linked accounts which had the most engagement.
All the suspicious accounts in question have been suspended, noted Twitter's blog post.
Twitter said it has been working to curb the ability of foreign actors to manipulate its platform following revelations of Russian attempts to influence the 2016 election. Much of the content was focused on making these accounts look like a real life person was tweeting on the platform. Included in this total were an extra 1,062 Russian-linked accounts the company recently identified and then suspended mostly for violating its rules on spam.
Twitter also addressed the issue on Friday, announcing that it would notify nearly 670,000 users in the USA who followed, retweeted, or "liked" posts from suspect accounts during the election period.
"Consistent with our commitment to transparency, we are emailing you because we have reason to believe that you either followed one of these accounts or retweeted or liked content from these accounts during the election period". Note, the accounts have already been suspended.