Twitter has limited the number of accounts people can follow in one go, as tries to stop the rapid spread of spam and bots.
People will now be banned from following more than 400 accounts in an attempt to make conversations on the platform more "healthy". It already stopped them from following more than 1,000.
The move is part of a broad attempt to improve the platform, which has been repeatedly accused of encouraging disagreement as well as malicious and fake accounts.
Explaining the move, Twitter's head of site integrity Yoel Roth said 400 had been chosen as a "reasonable limit", which the company believes makes spam accounts less effective, slower and more expensive for perpetrators to operate.
Twitter found that almost half of all accounts which followed more than 400 times a day were engaging in so-called "follow churning", the process of repeatedly following and unfollowing the same account in an effort to grow followers, which is against Twitter rules.
"As a part of our commitment to building a healthy service, we remain focused on stopping spam and abuse on Twitter," said a spokeswoman.
"We found that having a high daily follow rate contributed to follower churn, and, as a result, we are reducing the daily follow rate limit from 1,000 to 400."
The social network predicts that 99.87% of Twitter users do not follow that many accounts per day, meaning it will not make any difference to the vast majority of people.
However, it said it wants to avoid burdening businesses which regularly use the platform to provide customer service via direct messages.
Verified Twitter accounts are able to follow a maximum of 1,000 accounts per day.
Additional reporting by agencies