When I bought my son a door jumper (basically a bowl with leg holes dangling from a spring that could be attached to a doorframe) I read all the safety warnings.
Here they are.
In case you don’t want to read all of them, there’s a bunch of obviously legitimate and potentially legitimate safety warnings, and there’s:
“NEVER use optional playmat with any product other than the door jumper.”
To be clear, the described item is a rectangle. Of vinyl-or-something-backed fabric.
And this throws all the other safety warnings into question. They’re taking their opportunity to warn me about danger to my child, and they’re using it to sneak in imperatives about combining a harmless rectangle with other objects. This doesn’t happen when you buy a yard of muslin from the store because you don’t expect a yard of muslin to come with any safety warnings at all. But when you look to a source for advice, and have reason to take it seriously, it may accumulate cruft:
Recipes on food packaging that call specifically for their brand, of that ingredient and any others the company sells. (If you’ve been carefully purchasing NESTLE® TOLL HOUSE® chocolate chips because you believe they’re essential to the recipe, good news, they are not.)
Institutions like banks and insurance companies, which might mail you important information you’d want to have, and might just be stamping “URGENT” on the envelopes because this improves some metric by getting you to open their random crap.
It’s happened to me in n medical setting, ROT-13 if you want the rkgen example; postpartum, a nurse told me that every time I used the bathroom I had to spray water on myself as a sort of makeshift bidet. “For how long?” I asked, assuming this had to do with heightened childbirth-related infection risk. “All the time,” she said, “For the rest of my life?” I said, and she nodded, and I never listened to anything she said ever again.
This is epistemic poison, but it’s all over the place. Attention is memetic energy; memes will evolve to grab it as necessary. Refer your friends (through privileged one to one channels they don’t tune out yet, of course) to gain in-game prizes! The next train is in two minutes on platform one, and remember, if you see something, say something. And we learn to saccade over ads and prune our Twitter feeds and filter safety warnings with our own judgment about the hazard level of vinyl-backed fabric rectangles so we can slog on through polluted informational waters, throwing out a few babies with the bathwater because the bathtub specified a brand of soap before reminding us not to bathe children near open windows.