Twitter deletes millions of accounts and turns off original tweeting feature

Latest update means Twitter users may notice a drop in followers

A single tweet from cybersecurity pioneer John McAfee can significantly affect cryptocurrency markets. (REUTERS/Lucas Jackson)

Twitter has quietly deleted millions of accounts and turned off a feature that allowed users to receive tweets via SMS messages.

It signals an end of an era for the 14-year-old social media platform, which was originally been built around SMS to send and receive 140-character tweets.

Twitter first removed the service allowing people to tweet via SMS message last year after CEO Jack Dorsey had his account hacked through the feature.

A hacking group called the Chuckle Squad exploited security flaws within the feature to tweet racial slurs and antisemitic messages from Mr Dorsey's account.

New vulnerabilities have since been discovered, meaning the Twitter via SMS service has now been disabled completely for most users.

"We want to continue to help keep your account safe," the company tweeted on Monday. "We've seen vulnerabilities with SMS, so we've turned off our Twitter via SMS service, except for a few countries."

Twitter added that "everyone will still have access to important SMS messages needed to log in to and manage their accounts".

The countries that still have access to the feature are those that "rely on it to use Twitter" due to poor internet connectivity.

As part of the latest update, Twitter also deleted millions of inactive accounts that were set up using SMS when the company first launched.

"We are removing accounts that were created via SMS as we no longer support this technology and because these accounts have a high risk of becoming compromised," Twitter said in a statement.

"As a result of this, some accounts may see a drop in followers. We want people to have confidence that their follower counts are meaningful, accurate and reflect active accounts on Twitter, and this is part of our ongoing work to ensure that."