Are you wondering if you're pregnant, concerned about your finances or looking to leave your spouse?

Even if you've Googled one of those issues, you probably don't want to start seeing ads for pregnancy tests, bankruptcy protection or divorce lawyers the next time you visit your favourite website.

A new report from the Privacy Commissioner of Canada has found some advertisers are being anything but discreet with their targeted ads, using sensitive search terms to push potentially embarrassing products to people reading news, sports and weather websites, based on past browsing history.

In the recently-released study, the Office of the Privacy Commissioner tested a series of non-sensitive and sensitive search terms to examine the types of information advertisers use to target people online. The OPC also checked to see whether advertisers were giving people the chance to opt-in or opt-out of targeted services.

Most targeted ads were based on non-sensitive information and offered a clear method to opt-out, but some were based on highly personal or embarrassing search terms that were used to advertise without the express permission of the user.

In a few instances, the OPC observed ad companies pushing bankruptcy solutions, divorce lawyers and liposuction services based on past search histories, occasionally without asking permission or offering a chance to opt-out.

"In a small but troubling number of cases, we were disappointed to still find some sensitive information being used to target ads without opt-in consent," Daniel Therrien, the Privacy Commissioner of Canada, said in a statement.

Therrien said this practice indicates the advertising industry "still has some work to do" with its targeted advertising practices.

"Some people like behavioural advertising becacuse the ads they see are more relevant to their interests," he said. "However, others do not like to be tracked and target in this way and the opt-out procedures for them need to be clear, consistent, and usable."

The OPC used a computer program to browse websites based on several non-sensitive key words like "European travel," "shopping" and "women's shoes," as well as sensitive topics like "HIV dating," "depression" and "liposuction." OPC researchers then navigated to various news, sports, weather and food websites to see what types of advertisements appeared.

Of the 9,000 advertisements reviewed, the OPC identified 300 that were behaviourally targeted. The majority of those targeted ads were labelled as such, and included a button to opt out of the targeting. They were also mostly based on non-sensitive search terms.

However, the study identified 34 ads that were targeted based on sensitive topics, including a few placed by Google involving bankruptcy and divorce lawyers. These ads were placed using an opt-out model of consent, contrary to a 2011 OPC recommendation that calls for such topics to be opt-in only.

The study also identified four organizations that placed behaviourally-targeted advertisements without identifying them as such. These ads from Google, Flyertown, MediaMath and AppNexus also failed to offer the user a chance to opt-out.

The OPC report says advertisers are getting better at offering opt-out options, with 96 per cent of targeted ads featuring the AdChoice opt-out icon. However, the OPC says that number should be a full 100 per cent.

"Advertising organizations need to ensure that knowledge and consent is provided for all targeted ads," the report says.

The OPC recommends consumers learn to control their Internet cookie settings and install browser plug-ins to protect themselves against unwanted advertisements.

"Consumers should also take advantage of the opt-out procedures that are available, even if they can be difficult to use," the report says.