Unobtrusive AJAX/jQuery Star Rating Bar - Bot Voting Protection
Have you noticed that vote (or poll) results on your website are not as accurate as you thought they would be? Web bots are to be blamed for this trickery. They follow each link on your page and voting links are no exception. Voting scripts usually allow one vote per user and ban any further voting attempts from the same IP address. So, web bots are allowed to vote only once, just as any other visitor. Each of them will hit the lowest rating link first, vote and make the total score for item lower then it would really be unless you somehow manage to ban them from following the voting links.
To tell a web bot or a robot not to follow particular link we use “rel” attribute of the <A> tag with its value set to ”nofollow”. This is enough for Google, Yahoo and other search engines’ bots but it will not stop other, somewhat more “curious” bots, from following the link. (more…)