Since 1984, new buildings in Germany must have a residual-current circuit breaker for wet rooms. Since 2007, every newly installed socket circuit of up to 20 amperes needs one. The usual trip current is 30 milliamperes. Year after year, people die when electrical appliances fall into full bathtubs.
Germans still usually call the device the FI-Schalter, although the trade now says RCD. When it trips, they say der FI ist rausgeflogen, the FI has flown out. Older private installations need not be retrofitted, except after certain renovations or where there is an obvious danger.