Another point along with home defense firearms & alarm systems is being alert to any warning signs or odd behavior.
The Fox station in the Dallas/Fort Worth Texas area has done a few news stories about a crook who poses as a gas company employee.
He's brazen & walks right into businesses w/o much notice.
Disguises & fake uniforms are not uncommon with some advanced criminals in 2013.
It always amazes me how much personal information people will give you or how careless some office workers are with employee contact details(phone #s, email addresses, home addresses, etc).
In Feb & April, I worked a short term security detail for a major film/TV production company in Stamford CT. I would see office notes & documents with personal data on it often. When it was no longer needed, I'd shred it or throw the company forms in a Iron Mountain container so no stalkers or crooks could dig it up later.