We hear everything and everything. What is already clear is that it depends on the country, since each country has its own laws.
Already, there is nothing legally concerning « urbex » as a practice. To find an answer to the question whether urbex is legal, we must look at private property laws. And that depends on the country. In my case, France, the rule being that the violation of private property as such is not punishable by law, unless the person entering your property commits theft or damages an object present.