This is NOT true. A GFCI can protect against fatal shocks, however offers absolutely no protection against electrical shocks in general. The current required to trip a GFCI breaker is enough to be very painful at the very least.
Personally I do not recommend that option outside areas not recommended for GFCI protection (e.g. kitchen count tops near the sink, bathroom). Even then I state that the addition of a ground conductor can further reduce risks of** dangerous** electrical shocks.