The names of 33 of the 40 talent show contestants, including Scottish singing sensation Susan Boyle, have been registered by cybersquatters, according to PR firm Speed Communications.
Many of the users have snapped up the .com and .co.uk domain names and now just six .co.uk web addresses remain unregistered.
Just five contestants registered web addresses in their name before entering the talent contest.
Guitar player Martin Macham and dog trainer Jackie Prescott are the only two contestants that have as yet completely escaped the clutches of cybersquatters, according to Speed.
Stephen Waddington, managing director of Speed Communications, said: "The winner of 'Britain's Got Talent' could find it pretty tricky to establish a strong presence online if they don't own a web address in their own name.
"Often fans will affix .com or .co.uk to the end of an act's name and expect to be taken to their website, but this might not be the case.
"Although many of the domains will just be holding pages, some could potentially contain explicit material, which could seriously damage an act's reputation."
Cybersquatters have also created 18 Twitter accounts in the names of the semi-finalists.
Research by the agency found that only four acts registered accounts in their name on the microblogging site -- Brit Chix, Merlin Cadogan, Darth Jackson, and Faces of Disco.
Waddington said: "It's not just celebrities that are affected by cybersquatting. Brands can often be targeted, particularly on social networking sites such as Twitter.
"Companies should register accounts in their name on these sites as a precaution, as well as common misspellings of their brand names.
"This is important as some users can accidentally mistype web addresses and visit sites such as gooogle.co.uk by mistake."
This article was first published on brandrepublic.com