Twitter CEO Linda Yaccarino has tweeted a defense of the temporary cap announced July 1 on the number of tweets users can read in a day, and the company said advertising has been stable in the days since the step that drew heavy criticism from users and marketing professionals.

Yaccarino wrote in her Tuesday tweet: “when you have a mission like Twitter — you need to make big moves to keep strengthening the platform.”

According to a Reuters report, it was her first public comment on the limits announced on Saturday by owner Elon Musk, who said the step was meant to discourage “extreme levels” of data scraping and system manipulation.

In the days since Musk’s announcement, Twitter users posted screenshots showing they were unable to see any tweets, including on the pages of corporate advertisers, after hitting the limit. And marketing professionals said it could undermine Yaccarino‘s efforts to attract advertisers.

Twitter said only a small percentage of people using the platform have been affected by the limits.

“To ensure the authenticity of our user base we must take extreme measures to remove spam and bots from our platform,” the company said in a blog post on Tuesday.

The limit took effect soon after Twitter began requiring users to log into an account on the social media platform to view tweets.

Facebook parent Meta Platforms has said it plans to launch a microblogging app called Threads, a rollout that represents a direct challenge to Twitter, which has been heavily criticized since Musk bought the company for $44 billion in 2022.

Asked in an email why the CEO did not comment on the move until three days after it was announced, Twitter did not comment but sent Reuters a poop emoji, the company’s standard response to media inquiries.