24 years ago today, hardliners within China’s government cracked down on student protests in Tiananmen Square with a hail of bullets, killing hundreds, possibly thousands. The event has been all but completely scrubbed from China’s historical record: today, words and phrases as benign as "today," "June 4," and even "May 35" are scoured from web services like Weibo. But dissidents have found one way to sneak references to the tragic event online: memes.

Quartz has posted a look at some of the best takes, including a photoshop of the classic ‘Tank Man’ image incorporating the big yellow duck from Hong Kong’s Victoria Harbor, pictured above. ("Rubber duck" has since been removed as a search term by Sina Weibo.) Another take (above), spotted by BuzzFeed uses Lego. Yet another re-enactment (below) with a cow and bulldozers was spotted by South China Morning Post.

Dealing with the constant scrutiny and filtering of internet activity under China’s Great Firewall has led to some inventive solutions, like using code words to talk about political figures. As thousands gathered today in Hong Kong and Macau to hold vigils memorializing the 1989 massacre, dissidents in mainland China resort to protesting covertly, trading image links online. But as long as people keep policing China’s web services for references to the June 4th Incident, it only seems to harden people’s resolve. "At least the Sina [Weibo] censors remember," wrote film director Jia Zhangke.