The users have found a way to "bomb" Google to improve the rankings of particular webpages, and ensure a site is near the top of the results for particular search phrases.

Before now Google's method of ranking webpages was thought to make it largely immune to the tactics that many businesses use to improve their position in web searches.

Some fear it is only a matter of time before businesses start using the bombing tactic to influence their standing in search results.

Bombing run

Like many other search engines, Google regularly crawls the entire web to find out just what is out there in cyberspace.

But, unlike some other search engines, Google does not trust webpages to accurately summarise what they are about.

Instead of just looking for keywords, Google also ranks a page's importance by the number of other sites that link to it and the phrases they use to describe the link.

A page that a lot of people have found useful on a particular subject will be ranked higher than one that no one else refers to.

Google also rates new webpages and links higher than old sites and referrals.

By exploiting both these working methods, some net citizens have found a way to artificially influence the rankings of the webpages that Google returns when people search for certain phrases.

First strike

The practice of influencing Google in this way was first mooted by Adam Mathes last year.

Mr Mathes runs a weblog, an online journal of his thoughts and interesting links he has found.

He first used a bomb to ensure that whenever anyone typed the phrase "talentless hack" into Google they got the site of his friend Andy Pressman.