Java Jive wrote:

On Tue, 14 Dec 2010 11:30:47 +0000, Ronald Raygun
wrote:

Locking it from the inside is dangerous - you don't want to have to be
finding and fiddling with a key in a panic when there's a fire and you
need to get out in a hurry. But perhaps even this is too rational and
hence unconvincing.

Not really much more dangerous, given there's a fire anyway.

Eh? The door is your means of escape. If you can't find the key,
you're in trouble. Remember there may be dense smoke, so if you
simply drop the key on the floor you may not be able to find it again.

You may choose to leave the key in the lock, but that's not very good
either. For one thing, if one of you is in, and the other is out, the
one wanting to come in may not be able to get the key in the door.
There's always the doorbell, but if the one on the inside is having a
heart attack... For the other, if you leave the key in the lock, then
the burglar can also get in, having smashed a panel.

But
which is more likely? Fire, or burglary? I'd say the latter,

Agreed.

and the
latter is a very good reason for locking the door from the inside as
well as from the out.

Not really. If anyone's in, a burglar is going to high-tail it out of
there pdq, in most cases. Aggravated burglary with violence is very
much rarer than ordinary stealthy burglary. Perhaps as rare as fire.

If the door has glass or thin wood panels, it's
easy to break in by breaking the glass or panel next to the latch and
reaching in and opening it from the inside. It's a second or two's
work, literally, before thugs are inside and able to threaten you.

If you make the door too secure, they'll just use a window instead.