Twitter has sacked around half of its 7,500-strong staff as part of its new owner’s efforts to cut costs. 

Twitter workers around the world were shown the door over the weekend, and many took to the site to vent their frustration and disbelief at the move. 

“Woke up to the news that my time working at Twitter has come to an end. I am heartbroken. I am in denial,” said Michele Austin, Twitter's director of public policy for the US and Canada. 

Twitter's new owner, billionaire Elon Musk, says he has been looking to find new ways for Twitter to make money. 

He recently paid US$44 billion (AU$68 billion) for the company, despite it seldom posting any profits in the years since it became publicly traded. 

Mr Musk had to take on billions of dollars in debt and sold US$15.5 billion worth of shares in Tesla, his electric car company, to secure the deal.

“The activist groups have been successful in causing a massive drop in Twitter advertising revenue, and we've done our absolute best to appease them and nothing is working,” Mr Musk said on the weekend.

But his presence could have the opposite effect, with Mr Musk's well-known disdain for content controls spooking many of its main advertisers, which are Twitter's main source of revenue. 

In another attempt to bring in more money, Mr Musk has launched a US$8 monthly subscription for Twitter with a blue check for users who want to pay for it. 

The blue check was previously given to ‘verified’ accounts on the platform, but could soon be available to anyone who wants to pay. 

Twitter says users who “sign up now” can receive the small blue graphic next to their names “just like the celebrities, companies and politicians you already follow”.

Some are concerned that opening up the ‘blue check’ system will create confusion and the rise of disinformation, for example, if impostors pay for the subscription and use the names of politicians and election officials to influence votes.