I have always been fascinated with different fighting/defense methods. Systema looking very interesting.

When I was searching I came across a site that lists some schools: http://www.russianmartialart.com/main.php?page=affiliates&loc=us

It states: "Only the schools listed on this page are currently certified and recognized to teach Systema as presented by Vladimir Vasiliev and Mikhail Ryabko."

Can't really prove how legitimate they really are, but it is a start.