@martinus @leah I disagree. If you tell a remote entity, eg by registered mail to the CEO and board or similar, that they are forbidden from accessing your server at all for any reason ("withdrawing implied rights of access") then in the UK at least all continued access is unauthorised and illegal.
It is an approach that I have used a few times to keep out persistently badly behaving identifiable bots and spiders.
@EarthOrgUK @leah I do not approach any CEO, I just use the method described and guess what? My webserver statistics show me that scraping is, more or less, done. There is still some scraping, but those are either bots from individuals that are not mentioned in the .htaccess file or in the firewall, or brand new bots that I wasn't aware of.
It's a continue job, which is, now it works, fun to do.