The JavaScript frame busting methods are not the right approach, you have no control over what his users see. There is no reason he can't filter out any JavaScript or other HTML. In fact he might not even display your live HTML. He might have copied it to make his page templates and it scraping just the data from your site, you just don't know. If he isn't doing this now, he will if he gets in an arms race with you.
You need to return bad data to his site by IP address and possibly user-agent. Don't make the data bad to mess with the users, just make it return unusable data, for example all numbers are zeros. Then what you do it make a scheduled task that scraps his website (using his domain name). If you start getting HTTP requests in your logs that correspond to the schedule job you created then you add the new requesting IP to the blacklist of funny data, then make a second request to his website validate the IP you blacklisted. You could setup your scrapping tool to use random tor exit nodes and cycle the user-agent info.
He could do the same (random ips) but might not... Really you need some type of accountability which you can never have on a public website but requiring registration/authentication would help some if it becomes that important to you.
You need to return bad data to his site by IP address and possibly user-agent. Don't make the data bad to mess with the users, just make it return unusable data, for example all numbers are zeros. Then what you do it make a scheduled task that scraps his website (using his domain name). If you start getting HTTP requests in your logs that correspond to the schedule job you created then you add the new requesting IP to the blacklist of funny data, then make a second request to his website validate the IP you blacklisted. You could setup your scrapping tool to use random tor exit nodes and cycle the user-agent info.
He could do the same (random ips) but might not... Really you need some type of accountability which you can never have on a public website but requiring registration/authentication would help some if it becomes that important to you.