A neighbor just told me about a current surge of emails circulating widely these days (and recent TV news reports) about how easy it has actually long been for burglars to open most home door locks (latch and deadbolt,) as well as keyed padlocks, etc., using a technique called "Lock Bumping" or "Key Bumping".
Burglars already know this, maybe we should too.
SNOPES.com has an excellent factual article that puts this very real security risk into perspective. YouTube also has many good videos showing how it works. One of the better YouTube videos is by Master Lock, also shows the kinds of new locks being invented to stop Lock Bumping.
As always, combining multiple security measures at each entrance should be considered, consistent with what you personally feel is a reasonable trade-off between security and convenience, not unlike a decision whether to add an anti-theft system to a vehicle.
This and other persistent "Alerts" are accessible on this blog at the menu Other Information