Ok this is not exactly blackhat seo however it is a deliciously evil idea and if it works it can rank your site up in Google. Can you get your biggest competitor banned from search engines? For example you use xrummer to spam their domain name to 500k sites in 1 day. Use your imagination and reply with some ideas. The goal is basically to kill off your competition. If this is impossible answer this. If you could do it...... would you?