Stay one step ahead of the fraudsters with our series of articles giving you the lowdown on the scams they use to trick people out of their hard-earned cash - and how to avoid being taken in by them.
This week, the unscrupulous criminals preying on cancer patients with fake offers of cannabis oil.
How does it work?
Many people believe that cannabis oil can help those with cancer, leading to a boom in the number of people buying cannabis oil over the internet.
Unfortunately, however, many of those who pay for cannabis oil online are being scammed by fraudsters.
In some instances, the criminals behind these heartless scams offer low-grade oil with no potential medical benefits at an exorbitant price. In others, they simply take people's money and send nothing out in return.
The charity Cancer Research UK said: "We have become aware that scammers are tricking cancer patients and their families into handing over money for 'cannabis oil', yet receiving nothing in return.
"At least one of these fraudsters is using the email address email@example.com and claiming to be based at 407 St John Street, London, which is the address of our London office.
"But the email address given has nothing to do with Cancer Research UK or our employees."
How can I avoid being caught out?
The world of internet medication is a murky one that is generally best avoided if you are worried about being scammed.
Certainly, Cancer Research UK advises cancer patients and their families not to buy cancer treatments of any kind online.
Instead, it recommends calling its information line on 0808 800 4040 with any questions about cancer or treatment, whether conventional or alternative.
You can also find more information about cannabis and the treatment of cancer on its website.
I've been defrauded. What should I do?
Most of the companies offering dodgy medications over the internet are unregulated, which makes it harder to get your money back if you are caught out by a scam such as the current one involving cannabis oil.
However, you may be able to help bring the perpetrators to justice by reporting the scam to the police via Action Fraud, which you can contact on 0300 123 2040.
"If you believe you have been a victim of this fraud, please contact the police," Cancer Research UK said.