if you are really that suspicious then make sure next time you tell your real estate agent to inform any potential tenants or purchasers to not take any pictures of the property due to "personal reasons".

no need to lose sleep over all these minutes things. taking pictures of the property does not mean someone is going to break in and steal your things and honestly, if your house has been earmarked for robbery, even if you have 10 tier security, your house WILL be broken in.