I've encountered sites that do this kind of check before, and I usually just don't bother signing up.
It's usually the case that I didn't /really/ want to sign up anyway, but I needed something (that with a little effort I could find elsewhere)
It's usually the case that I didn't /really/ want to sign up anyway, but I needed something (that with a little effort I could find elsewhere)
Disposable email exists for a reason.
If your site is just a chat forum and you don't mind spammers, sure let people use disposable emails.
If your site involves money or auctions or credit cards.. letting disposable emails in can be very costly.
Now if you want to spam 500 million credit cards on my system, you are going to need to at least make them from some common domains, which I can block down the road. If you are using an email hiding service, way easier for you.
Not sure bitcoin matters, if I had users paying with bitcoin in an app I would STILL blacklist certain email domains.