Meitu is an Android and iOS app made by China-based developer Xiamen Meitu Technology Co., Ltd. The app adds cartoonish embellishments and facial feature distortion reminiscent of Japanese anime to selfies, and for some reason, became widely popular with Western users this week. Meitu is by no means new – it's been around since 2008. But if you went to sleep last night blissfully unaware of its existence, chances are you saw someone's Meitu selfie somewhere on the internet when you woke up.

Meitu brings a couple of things to the table. First, you can use the app as it's intended and apply effects to your own selfies. Take a selfie, add a silly filter, post to Facebook and everyone has a good laugh about it. But Meitu's effects can also be applied to other photos – cue much merriment and silliness on the internet. You can even keep feeding it the same image and re-applying filters until it no longer recognizes a human in the picture, which raises all sorts of existential questions.

But as quickly as it came into the spotlight, spoil sports put the brakes on when they looked closely at the app's code. CNET published an article cautioning users against downloading the app, citing privacy concerns. Twitter user and self-described 'security pessimist' @FourOctets posted an alarming message that the app was sending each user's unique phone identification number to a server in China. Jonathan Zdziarski, a security researcher, also tweeted some of his findings after combing through the iOS version of the app.

It all sounds pretty alarming, but Zdziarski doesn't actually see anything particularly malicious about Meitu. Or at least, nothing unique.

Another Twitter user theorizes that the app's maker is just complying with new Chinese laws.

So what do you think? Is Meitu nothing more than a data-mining scam? Or are you comforted by the fact that all of your other apps are spying on you anyway, so what's the difference? Let us know in the comments.