Dutch Report on False Glideslope Signals
Pilots might be startled by an unexpected pitch up.

The Dutch government’s safety board wants to publicize the existence of false glideslope indications that could cause the aircraft, when coupled to the autopilot, to pitch up rather than down. The insights were gathered during an investigation into a pitch-up incident on a Boeing 737 in which the incident "digressed" until the aircraft’s stick shaker activated.