Actually easyjet at least are remarkably low-tech, they have a printed list of names and all they do is look at the passport and cross off the name with a highlighter. OTOH BA now have machines into which you can insert any credit card in your name and it will figure out who you are and print you a boarding card, no people or tickets involved at all.
There's also the fact that fraudsters are mostly likely to want cash and not free flights!