As you know, Google + has been released, although it’s still in the testing phase, it has got a lot of attention. So far, the only way to get into Google + is by getting an invitation from someone that is already using Google +, but sadly, spammers have found a way to utilize this to send you spam messages.
Spammers have realized that Google + is the next big thing, so they have decided to utilize its popularity to send you spam emails. They have managed to create emails that look almost identical to the Google + invites, so you could easily be tricked to follow their link thinking that you’re going to sign up for Google +.
Anyhow, if you manage to get a Google + invitation, make sure that you double-check the person that sent you the invite. If you don’t pay attention and follow the link, you’ll end up on a pharmacy website that will try to sell you all sorts of medications.
So far, we don’t know whether these sites install any spyware or send spam messages to everyone in your email list. Therefor, it’s better to keep an close eye for these fake emails.