Thanks for your informative replies.
The other kind of latch that I have seen is a seperate entity from the latch, it looks like another smaller latch usually above the actual latch
I guess that's the one I'm talking about. You can see a picture on the cover page of
this PDF (I believe that's the 2030A model on the inside pages). The difference is that the anti-thrust thingy is below the doorlatch rather than above--intuitively, that looks like a better position to me.
In the US at least, you can buy a plate that fits on the side of the door, which helps to prevent access to the latch
They also have the advantage (over anti-thrust bolts) of being visible, thus possibly deterring the thief from wrecking your door in a fruitless attempt in the first place, no?
Vector40:
you must make sure the door is mounted tightly enough to the frame
Good point there. Fortunately, in most residential places that shouldn't be hard to fix.
Pretty much all modern doorknobs have them.
Careful with those generalisations, where I am, it's been years since I last saw one on a door. None of the new buildings I have visited lately have them--in fact what they do generally have is a combination of individually good quality parts, linked by some
very weak point, such as the case of the small frame offset in the pictures I posted above.