They have been in many situations, like business, gov security agencies etc
There is another similar system being supported by GRC which David asked for us to look at and it can tailored as a login sequence for those wishing it. RFC Possibility SQRL - #22 by Onaka And follow the links to GRC website and it will answer a lot of your questions. So rather than we take up forum space answering your questions which will be ever increasing as we answer the one already asked, just read the GRC site about this topic