Despite what you may have read in the frenzy of stories over the last few days, the people you follow or simply check out while browsing on Instagram will not get a notification when you surreptitiously take a screenshot of their posts. That is, if you're creepy enough to do that in the first place.
That's right: if you really, really want to save that photo of your friend's giant lobster roll or the one occasional photo you actually enjoy from your friend's endless stream of black and white architecture shots or whatever, then screenshot away. It's definitely kind of creepy, but rest assured nobody will know. (Unfortunately, that's not the case for what you've liked). However, people will get a notification when you screenshot one of the new disappearing images or videos they send to you via Instagram Direct messages, according to a report by The Verge.
But as a Mashable points out, there's actually a better way to save Instagram photos that doesn't involve cropping screenshots, and best of all, you'll get a higher quality version of the image. It takes a few extra steps, though.