Twitter began the mass removal of its blue ticks on Thursday, as the symbol previously used to signify a verified account vanished from users including the Pope, Donald Trump and Justin Bieber.

Owner Elon Musk, who has seen his $44 billion investment in the site shrivel, earlier pledged to get rid of what he described as a "lords & peasants system."

He offered instead to sell the blue badge to anyone who would pay $8 a month, in a move he said last year would "democratize journalism & empower the voice of the people."

Earlier dates set for the rollback of the ticks -- predominately used by celebrities, journalists and politicians -- have slipped by without noticeable action.

But on Thursday high-profile accounts, as well as those of many reporters at AFP and other news organizations, appeared to have had the checkmarks removed.

Politicians and official bodies also appeared to have been hit, with US Senator Brian Schatz objecting to the possible effect on public confidence in the event of disasters.

"There really ought to be a way for emergency managers to verify that they are real on this website or imposters will cause suffering and death," he tweeted.

"I am not complaining about my own check mark, I just think during natural disasters it's essential to know that FEMA is actually FEMA," he wrote, referring to the Federal Emergency Management Agency that steps in after hurricanes and deadly storms.

Some celebrities still had the blue tick, despite not signing up for it.

Musk said in response to a news article about those check marks that he was "paying for a few personally."

In response to another tweet, he said it was only for Star Trek's William Shatner, basketball superstar LeBron James and author Stephen King.

Media labels gone 

The removals followed spats between Twitter and various news organizations that have objected to labels appended to their accounts indicating they were "state affiliated" or "government funded."

But those too had disappeared from many high-profile media accounts, according to a review by AFP.

As of 0600 GMT Friday, they no longer appeared on the Twitter accounts of US radio station NPR, Canadian broadcaster CBC, China's official news agency Xinhua and RT of Russia.

Twitter had long labelled accounts linked to state media or government officials, especially from China and Russia, saying the policy focused on entities that were "the official voice of the nation state abroad".

Recently, however, the labels were applied to news organisations that received public funding but were not controlled by any governments.

NPR stopped using Twitter after it got that tag, and CBC followed suit.

Radio New Zealand also threatened to leave Twitter this week over the "government-funded" label, while Sweden's public Sveriges Radio said it would stop tweeting.

It was not immediately clear why the labels were removed, but the change was praised in some quarters.

"I support Twitter's removal of all 'State-affiliated media' labels," tweeted Hu Xijin, the former editor of Chinese state tabloid Global Times who rose to prominence on the platform as a voice of strident nationalism.

His account was no longer tagged as affiliated with the Chinese state.

Ad income plunges 

Musk's tumultuous ownership of Twitter has seen thousands of staff made redundant and advertisers fleeing the platform.

Users complain that hate speech and misinformation have proliferated and accounts with extreme views are gaining traction due to less content moderation.

This month, a closely watched forecast said Twitter's income from advertising will fall by a large margin in 2023.

Analysts at Insider Intelligence said they were slashing an earlier worldwide revenue estimate of $4.74 billion by more than a third to $2.98 billion as trust deteriorates.

According to research firm Pathmatics, 14 of the top 30 advertisers on Twitter have stopped advertising on the platform since Musk took charge on October 27.

Insider Intelligence noted that Musk's efforts to build up a subscription service "won't make up for the lost ad revenue."