Is there a reason there's no naming and shaming going on here? One company asked me to do an implementation of the Bay Area MUNI network which fetched live updates of the locations of all buses every 10 seconds; there was more to it but I can't remember it now. This was to be done in React with D3 and no additional libraries were to be used to help with integrating D3 maps in React. The role was junior level, the job…
No, there is no rule, unless you signed a contract stating you will never disclose any interview information, and even then, they'd have to find your post, find out who you are, and then take you to court over an extremely shaky premise.
Just name the damn company people! You're giving companies far more credit than they deserve in these situations. I'd argue you owe it to other people who may follow in your steps to know when a company is exploitative, deceptive, or just plain corrosive.
edit: now with less snark