I’m not entirely sure how cheques work being that I’ve not used one in about 15 years, but I’d imagine they give a cheque from an account with no money. Because cheques are awful the money will appear in your account for a time period by which you are given the illusion of getting legit money. They ask you to buy something like jewellery or gift cards and ask for it back at the end, maybe letting you keep a bit of it for yourself. A while goes by and the cheque bounces, which means you’re then on the hook for the cost of everything you purchased and the scammer gets a ton of free items that they can then sell on.
I do, but only because the UX around federated entities isn’t great at the moment. There’s no doubt that it could be made way more intuitive and streamlined for the average user, and that more effort could be put into migration between federated entities so that it doesn’t feel like as much of a chore to jump between instances. The average user won’t care about federation, and they just want to quickly get some content.