Just imagine that kids or burglars are casing your house. They might trip the main electrical breaker and wait a couple days before gong back. Why? Your security system, if you have one, will be dead. Your powered security cameras, your VOIP telephone, your internet modem and router will all be dead.
Unfortunately, your refrigerators and freezer will also be off potentially causing damage and losses.
Locking your exterior breaker box is the right thing to do.
JP at Home Watcher LV