Social media companies Snap Inc. and Twitter Inc. both saw shares tumble Feb. 22 following recent changes to the companies' platforms that have stirred strong reactions from some users.

Snap's stock saw the bigger slide, with shares down about 7.5% as of 1:30 p.m. ET Feb. 22. The company has seen a surge of pushback about a recent update to its Snapchat app, which some users have complained they find confusing and difficult to use.

The update was the target of an online petition drive calling for Snap to roll its app back to the prior version. Snap on Feb. 20 responded to the Change.org petition by promising a new update to help users "uncomfortable" with the changes. It said changes were coming soon for iOS and Android to help users better sort information to align with their personal preferences. The petition had amassed about 1.2 million signers as of midday Feb. 22. Celebrity Kylie Jenner jumped into the fray Feb. 21, posting tweets critical of the Snapchat update and suggesting the app's usage was falling.

Meanwhile, Twitter's shares were down about 3.5% as of 1:30 p.m. ET Feb. 22, the day after the company announced new rules designed to crack down on using automated software or bots to spread spam or otherwise attempt to "subvert or manipulate [a trending or popular] topic, or to artificially inflate the prominence of a hashtag or topic."

The rules specifically ban users from posting identical messages or content from multiple accounts, or from simultaneously performing tasks such as liking, retweeting or following from multiple accounts. Exceptions are made for apps used to share weather, emergency or public service announcements.

A hashtag #twitterlockout was being used by some users critical of Twitter's new rules and its impact on their accounts, with some accusing the company of censoring conservative voices in particular.