The man who came up with Twitter's retweet button has likened it to "handing a four-year-old a loaded weapon", in an interview with BuzzFeed.
Developer Chris Wetherell said no-one at Twitter had anticipated how it would alter the way people used the platform.
Twitter has been criticised for allowing the spread of bullying, hate speech and fake news.
Founder Jack Dorsey has previously spoken about the need to demote likes and follows.
The retweet button was built in 2009 by a team of developers led by Mr Wetherell, and quickly became an integral part of Twitter.
He told BuzzFeed that he thought the retweet button "would elevate voices from under-represented communities".
Previously people had to manually retweet each other by copying text and typing RT and the name of the tweeter but once the process was automated, retweeting meant popular posts quickly went viral.
While some went viral for good reasons, such as providing information about natural disasters, many others were not so benign.
Gamergate - a harassment campaign against women in the games industry - was one example of how people used the retweet to co-ordinate their attacks, Wetherell told BuzzFeed, describing it as a "creeping horror story".
"It dawned on me that this was not some small subset of people acting aberrantly. This might be how people behave. And that scared me to death."
Following the 2016 US presidential campaign, when a huge amount of disinformation was shared on both Twitter and Facebook, both platforms came under the scrutiny of governments around the world.
Twitter remains under pressure to tweak the platform to make it a less toxic environment.
At the TED (technology, entertainment and design) conference in Vancouver earlier this year, founder Jack Dorsey said the firm was considering demoting likes and follows, adding that in hindsight he would not have designed the platform to highlight these.
He admitted that Twitter currently incentivised people "to post outrage".
A similar thought occurred to Mr Wetherell, he told BuzzFeed.
"We put power in the hands of the people," he told the new site. "But now, what if you just say it slightly differently: Oh no, we put power into the hands of the people."