I had a call a few years ago from a woman saying she was a customer and was really unhappy with my work, after about 30 seconds of moaning she very quickly says "yeh well my husband is a window cleaner in this area so back off or else" then she put the phone down before I could answer. it was days before I dare leave the house without and armed escort.
I made a point of targeting the area after that, and so far no one has had the balls to say anything to my face. :
If any newbies start up near me I try to help if possible. They are gonna start anyway so would rather have them as friends.
And anyone who upsets me gets targeted.