For some dishonest or ill-informed Twitter users, Hurricane Harvey is the perfect storm … for scoring some sweet, sweet retweets.

Hurricane Harvey, a Category 4 hurricane currently ravaging the Gulf Coast, brought scammers out of the woodwork over the weekend as doctored or decontextualized images that were tagged onto the Hurricane Harvey narrative made the rounds online.

It isn’t uncommon for fake photos to pop up in the wake of a catastrophe, and people often have difficulty recognizing when an image has been manipulated, so it’s understandable that some of these images have gotten so much play online.

The impulse to “retweet to save a life” is an altruistic one, and often users unintentionally share false information with good intentions. But spreading misinformation in the midst of a disaster is dangerous and may very well prevent people affected by the hurricane from getting the aid that they need, like the reposts on Facebook and Twitter citing an insurance company’s number as an emergency hotline, according to a report by BuzzFeed.

Here are the images posted under #HurricaneHarvey, or associated tags, that actually have nothing to do with the current weather crisis in Texas.

The infamous highway shark

This image seems to surface every time a major city experiences flooding and every time people fall for it. The picture is fully doctored — in a 2013 blog post by shark biologist David Shiffman, he broke down why this specific image doesn’t make sense, citing the water’s depth, the original photograph featuring this shark, and the fact that “to the best of my knowledge, there has never been a confirmed photo of a shark swimming in city streets following a storm.”

The airport disaster

The “Houston, we have a problem” joke was ripe for the taking in this scenario, and this Twitter user didn’t mind using a fake picture to bolster their wordplay. This image purportedly shows a flooded Houston airport but is actually an edited version of a photoshopped image of LaGuardia Airport, originally used to demonstrate the projected impact of climate change. Down the rabbit hole we go.

The Cajun Navy

The Cajun Navy, a volunteer group that formed in the wake of Hurricane Katrina and dedicated to assisting victims of natural disasters, did actually make the trek to Texas to help those trapped by Hurricane Harvey. This image, however, is from a Cajun Navy relief effort more than a year ago, as pointed out in this tweet, but not before author Margaret Atwood retweeted it.

The unlucky reporter

If pressed on this tweet, the user would probably write it off as “satire,” but those who replied to it seem to be taking the GIF at face value. If it wasn’t already clear from the lack of CNN branding, this footage is not related to Hurricane Harvey, nor is it real. It’s actually a scene from The Class, a CBS sitcom that ran for one season in 2006. The woman in the GIF is actress Lucy Punch, and she was hopefully not hit with an actual stop sign.

The gator trouble

Yikes, Katie Couric! This alligator photo actually dates back to April but has been touted as an example of gators running amok in neighborhoods since the flood began. Couric eventually corrected herself after people pointed out that the photo was too old to be related to Hurricane Harvey.

The non-believers

But not everyone was taken in by the incorrect photo attributions. Some deleted tweets, like the ones citing an image of a family using a refrigerator as a floatation device that’s actually from another flood in the Houston area in 2016. Others issued corrections when called out.

Other people were quick to supply jokes about the hoaxes floating around, with one user even predicting the reemergence of the shark.

So, when sorting through images connected to any breaking news event, be sure to stay skeptical, and if all else fails, there’s always Google Images.