Albuquerque, New Mexico suffers from a more than usual amount of property crime for a city this size, and I recently found out about another way that thieves use to break into folks' homes...through garage doors.
They will make a hole with a knife or something sharp, and then cut a hole with tin snips, which can all be done very quietly, as it often occurs when the homeowner is asleep inside. This is usually done in the middle of the door, near the top, so that they can reach in and release the door from the rail above the center of the door. Then they just lift the door up quietly and steal any valuables inside.
While this technique is not particularly common, it is not too uncommon, either. Thieves specifically target "level 1" doors which are the thinnest and easiest to snip. Level 1 doors have no insulation and are made out of 24-25 gauge stamped steel. This kind of door is one of the easiest points of entry into a house.
There are some simple ways to prevent most garage door break-ins however. You can either detach your door release handle completely or wrap it around the J bar a few times to stop them from easily releasing it, or zip tie the release closed. If you need to use it, you will have to cut the zip tie first. Many garage door openers also feature an electronic lock button on the inside wall by the door, which can prevent remotes or frequency devices from opening the door from outside.Once you are in for the night, you can turn this on.
Slide locks are another option, but if you get a manual one and forget to unlock it, you can do some real damage to the door when you try to open it. Several companies, however, make automatic slide locks which prevent the door from being lifted up at all by means of a deadbolt that goes through the track. These locks will automatically disengage when you open the door.
Sadly, none of these options will help if the thieves just decide to snip the hole big enough for them to squeeze through, so it is always a good idea to lock the inside door with a deadbolt. If you don't have a bunch of cats that like to hang out in your garage, like I do, a further option could be placing a motion sensor inside the garage.