I have not read all the posts but the OP is basically uninformed.
A Glock has three safeties, four if you count the operator.
From:
http://pub6.bravenet.com/faq/show.php?usernum=500305377&catid=2475
How many Safeties does the Glock Pistol Have?
GLOCK pistols do not feature a conventional manual safety lever; however, they are equipped with the revolutionary fully automatic safety system consisting of 3 independent, mechanical safety devices. this explination is for the new glock owners and skeptics
1. TRIGGER SAFETY The trigger safety is incorporated into the trigger in the form of a lever and in the untouched state blocks the trigger from moving rearward. To fire the pistol the trigger safety, as well as the trigger itself, must be deliberately depressed, at the same time. If the trigger safety is not depressed, the trigger will not move to the rear and the pistol will not fire. The trigger safety is designed to prevent accidental firing when the pistol is dropped or subjected to an off-center lateral pressure or similar forc
2. FIRING PIN SAFETY The spring-loaded firing pin safety projects into the firing pin cutout and mechanically blocks the firing pin in the ready and/or loaded condition. When pulling the trigger to the rear, an extension of the trigger bar pushes the firing pin safety upwards, clearing the firing pin channel. During the cycling process the firing pin safety automatically engages with the help of the firing pin safety spring. The firing pin safety is mainly designed to avoid accidental firing should extreme forces allow a separation of slide and receiver assembly.
3. DROP SAFETY The following denotes the safety function of the trigger mechanism housing. The rear part of the trigger bar, which has a cruciform shape, rests with its wings in the loaded/ready position on a safety ramp located in the trigger mechanism housing. When pulling the trigger to the rear to the leave the safety ramp being lead downwards and leave the safety ramp being lead downwards and further backwards by the connector and finally separating from the firing pin. During the cycling process of the pistol, the connector is pushed inward by a ramp in the slide releasing the trigger bar, which is lifted with the help of the trigger spring and caught by the firing pin. This pushes the trigger bar forward and onto the safety ramp again.