If an alien crash landed on earth, probably the first thing that would happen to him is he’d get scammed and he’d have to fly back to his faraway planet in just his space undies. That’s if someone hadn’t stolen his identity and sold his space-craft already.

My wife and I were the proverbial ‘aliens’ a couple of years, when we flew into Cairo for a week’s visit as part of a round-the-world trip in 2010.We figured since it was so short a visit and all we wanted to do was see the Pyramids of Giza, the Egyptian Museum, take a cruise on the Nile and wander around the ancient streets that we’d not bother to buy a guide-book and just wing it.

Big mistake!

We got conned on our way to the pyramids.We got conned wandering the ancient streets. I got conned on an evening stroll when looking for a place to eat. Conned. Conned Conned. By old kindly looking men. By young boys. By exuberant fathers with stories about their children. It was incredible.

The scams were not sophisticated in the way they are in Australia and other westernised cities and “harmless” in the sense that all you lost was a bit of dosh. Looking back they were somewhat endearing (or perhaps pitiful) and assumingly thought-up as a means of getting by in a very tough city.

Back in Australia, it’s a far more dangerous proposition with greed the primary motive. There are scam-artists waiting on the telephone, in the letter box and at the front door. It’s so bad that the government has a dedicated website called Scamwatch to warn you about each of them with real-life stories and advice.

Our home phone, which we hardly ever use except for our internet service is a constant source of dodgy phone calls. We hardly ever answer it now, figuring that if it’s an important call, people will try our mobiles or Skype.

The other day I picked up the phone and  a woman proceeded to tell me she was from Microsoft support and that I had downloaded a virus on to my computer. She implored me to go on to my computer and search for a certain file to verify this. I could hear she was talking from a faraway place, and with a strange manner of speaking English, so I just hung up the phone. Sure enough this was a scam as described on this UK website with the end result that you download a real virus that steals all your personal information.

Then’s there’s the door-to-door energy salesmen trying to get you to switch energy accounts.

Twice this has happened to us in Melbourne. The first time the salesman identified himself as from an energy company, the second time was more sinister.

Last week, just before dinner, a guy appeared at our door with a clipboard. He pulled out a spreadsheet, told me he was from Jemena and said he needed to see my last energy bill to compare what I was currently paying.

Jemena is an energy infrastructure company which provides electricity and gas to homes. This electricity and gas is then on sold to consumers from retail suppliers like Origin Energy, who are our gas and electricity supplier.

The salesman gave me the impressions this was all very official and pressing so I rifled through a cupboard full of documents and on my iPad until I found an online bill. The man stood there quietly, smiling with his clipboard. I showed him the bill and he studied it. Then he said something like “Oh my god” and went on tell me I was paying 20 per cent more each month then  I needed to. He said he would sign me up and that I would save money from next month.It was then I realised this wall all a deceptive little scam.

He wasn’t from Jemena, but from a retail energy supplier called “Simply Energy”. I told him I wasn’t going to sign up to anything on my doorstep and he left with a piece of paper on which he had scribbled his mobile phone number in pencil in case I changed my mind.

I googled Simply Energy. The reviews were scandalous. It got an average rating of 1.4 out of 5 from 235 reviews on productreview.com.au with stories of customers being overcharged, having their gas and electricity supply cut and even contacting a customer’s current supplier to say they had switched to Simply Energy even when they never agreed to.

They use to call these people snake oil salesmen, referring to travelling charlatans selling miracle cures and quack medicines. Now the scams have become far more sophisticated and devious.

Have a look at the Scamwatch website, there are dozens of scams preying on the naive, weak-minded, plain unlucky or vulnerable from online auctions, to pharmaceutical products to real estate scams.

One of my most popular blog posts was about a letter I received in the post over a year ago covered with Spanish stamps and postmarks. It was addressed to me in person, offering me the chance to share in an inheritance of an oil magnate called “Albert Schlesinger” who had apparently died in a car crash in 2004.

Seems ridiculous right? Who would fall for that? But every year thousands of Australians do.

A program on the ABC’s 7.30 Report reported that every month, Australians lose $7 million just through internet scams.

They’re impossible to avoid unless you choose to live like a hermit, never answering the phone, turning on your computer or answering the doorbell.