Okay, so theoretically, I own a business in the good city of Langley or thereabouts. And a certain Jessica Yaniv waddles in, seeking to obtain goods or services. Is there a way to refuse a client that hasn't acted poorly to you yet, but you know that he might beat you with a cane or drive his scootypugg through your window? Pre-emptive restraining order? Little sign that says "We serve the LGBT+ community proudly, just not Jessica Yaniv"? How are vexatious, histrionic litigants usually dealt with?