What are the main useragents for the big search engines? In otherwords ... if you could only allow a set number of search engines to read your content what would they be ... at the moment i have ... "msn" "mozila" "googlebot" "Slurp" "yahoo" "Ask" "Jeeves/Teoma" am i missing anyone?
long story ... but i have a new site im ready to launch and i want to try to prevent spiders/bots/scumbags nicking my content so i will try and block them via the useragent. I know its not 100% but i simply dont want to block any of the big boys.
It won't work that way. The best defense against scrapers is to identify their hosting providers and send them DMCA takedown notices when they take your content without your permission.