The Tree Trimmer

This morning on my way to work I saw an older couple taking a walk. All of the sudden they stopped at some bushes, the old man pulled out some garden trimmers and started going to town on the bush.  Apparently it had overgrown the sidewalk just a tad, and that must have been unacceptable to him and his mate.The questions that came to me were: is it ok to trim someone else's property? is it so hard to just avoid the bushes that you have to trim them? And who carried trimmers with them? Seriously?!