Do warning posters work?

[Old Cruser]

I am wondering if others think a poster claiiming that our shed is alarmed works to deter the thieves or would they maybe chance it anyway?

http://www.saferderbyshire.gov.uk/news/news_items/burglars_given_alarming_warning_as_residents_arm_themselves_against_crime.asp

[Pete]

I think they would - why would a burglar risk it? There's plenty of sheds to rob, they would probably just move on to another house.