They can be fooled reasonably well (well enough to fool an iphone) with pretty simple techniques. For details, search for a bunch of articles from 2002 referencing Tsutomu Matsumoto's work.
> it can't be recorded by cameras
Well... http://www.theregister.co.uk/2014/12/29/german_minister_fing... https://news.ycombinator.com/item?id=12611155