Scammers are already exploiting Google+, using a version of the old survey trick by claiming to offer downloadable invites to the service.
With sign-up initially by invitation only, demand has been high. However, says Trend Micro fraud analyst Karla Agregado, responding to the invitation leads only to a list of surveys, one of which 'must' be answered in order to get a free invite - and which asks for the user's mobile phone number.
"At this point, it’s easy to realize that answering the IQ test is unrelated to the process of downloading a Google+ invitation, just like downloading a file is totally unnecessary to create a Google+ account," she says.
"This scheme does not lead to getting a Google+ invitation, only unnecessary charges to their phone bills, as the text at the bottom of the site implies that entering their mobile numbers will subscribe them to certain clubs, which will charge them specific amounts on a daily basis."
Meanwhile, some users are claiming that Google+Facebook, launched this week by Israeli company Crossrider, represents a security risk. RogueDarkJedi claims that the company is being 'deceptive' in claiming that the app is safe.
The app also changes search preferences to a site controlled by Crossrider, says RogueDarkJedi, and adds a signature to email messages sent using certain mail providers.
Around 100,000 people are believed to have downloaded the app.