I hate thieves, and burglars are especially hated in my personal world of villains. No, they are certainly not the most evil of common criminals, but stealing from ordinary people and violating someone's home is worse than bank robbery (not to mention that the banks are criminal organizations, too).
I was watching my local news last night when a story about a neighborhood plagued by a recent series of burglaries came on. The crooks were getting in through the doggie doors on these houses. They were committing their crimes in daylight, and "Beware of Dog" signs did not deter them in the slightest.
One older couple interviewed stated they had gotten rid of their doggie door already, but for prevention of a different sort of invasion, by possums, racoons, skunks, and other unwanted critters.
So just a word of warning, doggie may need to trade his freedom in exchange for a little home security.