This post has been updated.

Some Twitter users saw “Rape Melania” in their trending-topics boxes Sunday after images of a person holding a sign bearing the phrase during a Saturday-night demonstration in the District circulated on the social network.

Photos of the chilling banner, taken at an anti-Trump rally outside the president-elect's new hotel in the nation's capital, drew strong condemnations from Trump supporters and opponents alike. The online conversation — almost all of it about the sign's inappropriateness — placed “Rape Melania” on a list of trending topics for some, but not all, Twitter users. Twitter customizes trending topics based on who users follow and where they are located.

Many Twitter users who saw that “Rape Melania” was trending criticized the technology giant for not removing it from lists of most-discussed subjects. Responding to a Washington Post inquiry, Twitter emphasized that the phrase trended because people denounced it, not because people advocated sexual assault.

Something similar happened in March, when the hashtag #StopIslam trended after a terrorist attack in Belgium. The Post's Caitlin Dewey provided a helpful explanation at the time:

As disturbing as this hashtag might appear, however, it’s actually quite the opposite. #StopIslam is only trending now because thousands of people are criticizing it. . . .

The hashtag has been in circulation for at least five years, when it first entered the tea party-Twitter lexicon alongside bigoted mainstays such as #bansharia and #IslamIsTheProblem. It began spiking in Spain early this morning, when some trollish, right-wing Twitter users there began tweeting it.

#StopIslam didn’t really take off, however, until the backlash against it began.

Nevertheless, Trump backers have seized on the “Rape Melania” sign and the social media trend it launched to cast opponents of the next president as hypocrites whose objections to Trump's campaign rhetoric are now illegitimate.

Trump's critics, meanwhile, are stressing that a single sign does not represent all of them. And several told The Washington Post that they believe the person who held the sign might have been a Trump supporter trying to make the protesters look bad.