I got done in Prague, although it was 100% my own fault (left my passport & wallet in my jacket over my chair). A mistake you only make once.
I've been back a few times since and not had any issues.
It's a very walkable city - and as has been said, Uber works fine.
I'm not sure why people exchange money these days. Just use a "no exchange fee" credit or debit card wherever you go.