So, I've witnessed this horrifying thing where someone snaps a photo of, say, the floor, or a blank wall, and then uses the caption line to send their actual me

So, I've witnessed this horrifying thing where someone snaps a photo of, say, the floor, or a blank wall, and then uses the caption line to send their actual message. Packing roughly 60 bytes into 8 megapixels makes me cringe, although thankfully at least the backdrops are usually high compressible. Is this practice common, or do I just find myself around the wrong sort of bandwidth-sociopaths?