Wizarding Home Security

[cindysphynx]

No: HPFGUIDX 30962

I was thinking in the shower today, and I started wondering about the 
way wizards prevent other wizards from breaking into their homes.  In 
GoF, Sirius breaks into a wizarding home to use the fire while the 
occupants are away.  Also, Snape secures his office with a spell that 
Moody is able to defeat.  

>From that, I assume that your average wizarding family puts a spell 
on their home when they leave to "lock" the home, but someone clever 
like Sirius can break the spell.  The problem, though, is that Sirius 
almost certainly doesn't have a wand.  So how does he break into this 
wizarding home?

The answer, perhaps, is that he simply apparates from outside the 
wizarding home to the inside and back again.  If that is so, then how 
do wizards protect themselves against burglary-by-apparition?  
Someone like Pettigrew or Bagman or Karkaroff or Sirius (my, there 
are quite a lot of wizards on the run these days!) could survive 
quite nicely by raiding the refrigerator of the closest wizarding 
family.  Indeed, perhaps Sirius does not have to survive on rats in 
GoF because he could just keep popping into various wizarding homes 
and fixing himself a quick snack.  He says he is worried about 
stealing too much food in Hogsmeade, but perhaps the families 
wouldn't notice if he cleaned up after himself.  <bg>

Any thoughts?

Cindy (also wondering how on earth Wormtail and Crouch Jr. were able 
to trick paranoid Moody or break into Moody's home at the beginning 
of GoF)