Whenever you desperately want something, criminals have always come up with ways to rip you off.  It's a practice as old as time.

The Google+ invite frenzy has prompted some devious spammers to send out fake invitations.  Sophos, a cyber securities firm, first reported this spam.

Gmail users would receive a Google+ invite that looks like the real thing.  Except when you click on the link to the Google+ invite, it leads you to a website that sells erectile dysfunction drugs like Cialis and Viagra.  It even had a special 4th of July sale promoted by a woman wrapped in an American flag.

Online erectile dysfunction drug shops, of course, are rife with fraud.  So are websites selling easy ways to make money online and miracle cures for things that don't have easy solutions (like snoring, wrinkles, etc.)

This isn't the first time that insane demand for Google products spawned scams.  Back when Gmail membership was an exclusive club and a hot item, spammers sent existing Gmail users a notice that Google had just given them 50 extra invites. 

All they have to do is fill out a form with their Gmail password.

Apple, another tech darling, was also used as bait.  Back before the iPad was released, bogus Facebook pages were set up to ask users to be beta testers; they would get the iPad in advance and then keep it for free.

All these Apple fans had to do was provide their personal information and cell phone number.  Their cell phone number was subsequently enrolled in an expensive premium service.

For active Internet users, scams and spams are a fact of life.  Abiding by the following guidelines, however, will lessen the pain.

- Don't respond to sweet offers that you didn't pursue or don't know the origin of, whether it's a Google+ invite or a Nigerian millionaire giving you money.

- Don't ever give out your personal information to email requests from scammers posing as legitimate entities.  Legitimate entities will never ask you that; the only time they might prompt you for personal information is when you approach them do something.

- Too good to be true offers do exist, for example from academic or marketing experiments.  However, you have to make sure they're legit.  If you're not sure, don't go for it, especially if you have to provide your personal information or grant access to your computer in exchange for it.