Twitter Inc. banned some kinds of automated accounts and placed restrictions on posting simultaneously from multiple accounts, curbs that drew complaints Wednesday from conservative members who claim they are being unfairly targeted by the company.

Twitter updated its rules to prohibit users who operate multiple accounts from simultaneously tweeting, retweeting, liking posts and following accounts—a practice common among bot operators trying to coordinate activity across legions of accounts.

Social-media companies including Twitter have faced criticism over their efforts to prevent bullying and abusive content. The companies have tried to rein in such actions while at the same time avoiding the perception they censor unpopular opinions. Twitter in particular is focusing on cracking down on spam as a way to reduce the amount of fake news on its site.

Twitter’s actions caused an uproar among some right-wing activists. The hashtag #TwitterLockout began trending, driven mainly by users expressing dissatisfaction over their shrinking number of followers.

“Let’s get loud,” a post on the Twitter account of radio host John Cardillo said. “This is happening to all of us. Every conservative verified account I know, including me.”