There have been a few posts on my Friends Page in the past day or two - not least a link posted in rural_ruin
a little earlier - that draw attention to the fact that trespassing is generally illegal, and people who are taking nothing away but photographs are being charged and convicted.
I know that there is something of a culture of pushing people towards entering decayed and apparently abandoned buildings that pops up from time to time in this community, and I'd just like to remind everybody that, if you enter private property without permission then you are trespassing, and you do risk a fine or imprisonment in many parts of the world. For that matter, photographs posted in public forums such as this can and do constitute evidence.
Additionally, while I hope this is obvious, the nature of decayed buildings is such that they can be dangerous - if you are planning on exploring, please ensure that someone knows where you have gone, and take along a cellphone if you can.
Take care out there, people.