(Reuters) - Elon Musk's Twitter has put a temporary limit on the number of tweets that users can see each day, a move that has sparked some backlash and could undermine the social network's efforts to attract advertisers.

The limit, imposed to "address extreme levels of data scraping and system manipulation", is the latest change by Twitter, which was last year acquired by Musk for $44 billion.

What does the latest change mean and what are the alternatives to Twitter?

How do the changes impact users?

Users cannot view tweets without logging in to the platform. Verified accounts can now read 6,000 posts per day, unverified accounts 600 posts and new un-verified accounts 300 posts. After that, users will get a message that says, "rate limit exceeded".

Musk has said that limit will "soon" increase to 10,000 for verified, 1,000 for unverified and 500 for new unverified.

He has been pushing to make Twitter's overhauled verified service more attractive. Musk made Twitter verified - special badges that were earlier given to notable profiles - a paid subscription and introduced tiers like gray, blue and golden badges.

Why did Musk put the limit?

Musk said the limits would help tackle scraping vast amounts of data from Twitter by almost everyone - from AI companies and startups to tech behemoths.

"It is rather galling to have to bring large numbers of servers online on an emergency basis just to facilitate some AI startup's outrageous valuation," he said in a tweet.

The technology behind generative AI tools such as ChatGPT is trained on massive amounts of data taken from the internet that helps produce everything from poems to pictures.

What are users saying?

Several Twitter users complained, with "#TwitterDown" and "RIP Twitter" trending on the social network website over the past couple of days.

The limits especially impact accounts run by informational agencies, journalists and monitoring services as they rely on reviewing thousands of tweets every day.

The National Weather Service said it may be unable to see tweeted reports of severe weather and associated damage, and asked subscribers to use its office telephone numbers instead.

What are the alternatives?

Twitter-like platforms like Bluesky and Mastodon are the main alternatives. They saw a surge in users and activity soon after Musk announced the limits.

Bluesky, launched by Twitter co-founder Jack Dorsey and now in the beta mode, said it saw "record high traffic" on Saturday and that it was temporarily pausing new sign-ups.

Mastodon also saw its active user base swell by 110,000 on that day, its creator and CEO Eugen Rochko said.