And you may have even joined in.
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This is where users create a side-by-side comparison of a picture from now and one from 10 years ago with the goal of showing how hard aging has hit them.
Even celebrities are in on this trend.
But tech expert Kate O'Neill has started a big conversation on Twitter wondering if this is some sort of ploy that could be putting cybersecurity at risk.
She ponders how all this data could be mined to train facial recognition algorithms on age progression and age recognition.
Before you rush to delete your post, she says it's just a thought other tech experts are now digging into.
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Facebook, which also owns Instagram, issued a statement saying it had no role in starting the challenge and saw no benefit in it.