Shouldn't you at least be disallowing /show/* in robots.txt? Not that scrapers are necessarily going to respect this... but the way your set up it seems like this is semi-legit behavior.
user-agent: *
disallow: /
user-agent: Googlebot
allow: /While I don't necessarily agree with the concept of only allowing google to index your site, comparing a search engine which feeds you business to a company reselling your data with no attribution is not really fair in my opinion.
Of course, forging your user agent, disobeying robots.txt or scraping after you were told not to, is wrong ethically.