Site says that problem is relatively minor – for now
Reddit has banned "impersonation" amid fears about the rise of deepfakes and other forgeries.
The company said it had made the decision to stop the rise of posts that try and mislead users about what people such as politicians have said.
It comes as the use of deepfakes – misleading, often very convincing videos that put a person's image into another video – spreads across the internet.
Reddit will continue to allow such videos, when they are used for jokes or satire. But it will ban anything that is "misleading in a malicious way", according to a moderator.
The company said that impersonation was already one of the rarest problems that users report on the service. It made up only 2.3 per cent of complaints, according to Reddit's transparency report.
But it suggested that such behaviour could rise in the future.
"We also wanted to hedge against things that we haven’t seen much of to date, but could see in the future, such as malicious deepfakes of politicians, for example, or other, lower-tech forged or manipulated content that misleads (remember, pornographic deepfakes are already prohibited under our involuntary pornography rule)," the announcement read.
"But don’t worry. This doesn’t apply to all deepfake or manipulated content – just that which is actually misleading in a malicious way. Because believe you me, we like seeing Nic Cage in unexpected places just as much as you do."
The wording of the rule itself explains that it also bans using a Reddit account to impersonate someone, as well as linking out to websites that masquerade as others.
"Reddit does not allow content that impersonates individuals or entities in a misleading or deceptive manner," the new rule reads.
"This not only includes using a Reddit account to impersonate someone, but also encompasses things such as domains that mimic others, as well as deepfakes or other manipulated content presented to mislead, or falsely attributed to an individual or entity. While we permit satire and parody, we will always take into account the context of any particular content."