People looking to sell unwanted goods frequently turn to online classified sites. On Canada's self-proclaimed most popular classifieds site, Kijiji, users post new ads every .7 seconds.

Last week, an Ancaster, Ont., man disappeared after taking two men for a test drive in a vehicle he was trying to sell online. On Tuesday, police announced they had found Tim Bosma's burned remains.

The case raises concerns about how to stay safe when online transactions must include real-life meetings.

"When you're buying something, selling something, connecting through an e-commerce site, you need to recognize that not communicating with strangers doesn't work," one of the world's experts on digital safety, Parry Aftab, told CBC News.

'If you have an inkling there's something wrong, just stop and contact your local police services.'—Toronto police Const. Tony Vella

Though communication is necessary, both buyers and sellers must remember they are dealing with strangers and take precautions for their safety. "It goes both ways," said Aftab. "You are equally at risk."

Milwaukee police have started encouraging sellers to arrange to meet potential buyers at the local police station following a string of robberies, reports the Milwaukee-Wisconsin Journal Sentinel. Sellers and buyers have been both victims and perpetrators in these so-called crimes by appointment.

Joe Couto, the director of government relations and communications for the Ontario Association of Chiefs of Police, called doing business on the internet the "Wild West." He said the Milwaukee police initiative is "a good idea," but there is no Ontario police service doing something similar.

People should take precautions when selling things online, from the time they create an ad to the final step of accepting payment:

Creating an online advertisement

  • Limit the amount of personal information in the ad. Any information posted can be used by others for ulterior motives, according to internet safety site iLookBothWays. Reverse phone number and address directories can provide a wealth of information about the seller.
  • Think carefully about whether you should provide a telephone number. There are pros and cons to posting a phone number, said Toronto police Const. Tony Vella, adding he would post his phone number, but not his home address. "You can have a better feel for [a potential buyer] by speaking to the person," he said.
  • Stage photos to obscure identifying information. People taking photos of cars for sale in their driveway often unknowingly give away key information such as the house number and licence plate number, points out safety site iLookBothWays.

Communicating with prospective buyers

  • Get the buyer's information. If a prospective buyer calls, take down "as much information as you can and that person is willing to give," said Vella, such as: first and last name, contact number, home address and driver's licence number. Tell the buyer you will need a copy of their driver's licence before allowing them to test drive your car.
  • Conduct an internet search. "Google it," he said. Before you meet the person, search to see if anything suspicious pops up.
  • Arrange a meeting. Agree on a time during reasonable business hours either at home or in a public area, if the item for sale can be moved. For example, a car sale can take place in a public parking lot rather than a home driveway, said Aftab.

Before the meeting

  • Keep others in the loop. Let a friend or family member know the details of the meeting, and — if possible — arrange for someone to come with you or be present at home, depending on where the meeting is taking place.
  • Try not to let buyers inside your home. If the item for sale is inside the house, move it outside to avoid letting strangers in. If it's a heavy piece that cannot be moved, like a piano, in a closed-off area of the home, such as a basement, Aftab recommends having a second person stay upstairs while the seller and buyer examine the item.

During the meeting

  • Take photos. When the potential buyer arrives, snap photos of the person, their licence plate and their car, said Aftab. Then, text message those photos to a friend or family member who knows about the meeting.
  • Acquire ID. Ask the person to provide you with a copy of their ID, such as a driver's licence. The ID will not only give police a starting point if something goes wrong, but also "it's a bit of a deterrent for people," said Vella. Someone will be less likely to attempt to steal from you if you can provide police with a positive identification.
  • Keep a cellphone turned on and within reach.
  • Know your route. If you are taking someone out for a test drive, used car sale site Auto Trader suggests making sure a friend or family member not in the car know the planned route, estimated return time and your cellphone number.
  • Keep buyers in sight. If a buyer arrives with an entourage, do not let the people separate, advises safety site iLookBothWays. Scam artists like to split up, with one engaging the seller with questions and the other asking to use the washroom. Once inside the house, the person can perpetrate a theft.

Handling payment

  • Visit a bank. If you are accepting cash, do so in your bank so you can deposit the money right away. If you take a cheque, verify it with the bank that issued the cheque, not your bank.
  • Wait to transfer ownership. Before transferring vehicle ownership to a buyer, make sure you have received the full agreed-upon payment, warns Auto Trader.

While these precautions are great starting points, Vella stressed the importance of trusting one's instincts.

"If you have an inkling there's something wrong, just stop and contact your local police services," he said, adding it is "not at all" a bother to police who are happy to offer some friendly advice over the phone.

With files from Greg Layson