Around 23 million Canadians use Facebook every month, and with elections looming in Ontario, Quebec and New Brunswick and a federal campaign next year, those users will no doubt be besieged by political ads on the social media platform.

But unlike on TV and radio, political ads online are not strictly regulated.

They're also targeted at individual users or narrow demographic groups, making it difficult for the public to get an overview of the full range of ads being used in political campaigns and harder for media and watchdog groups to fact check the claims being made in those ads.

And despite recent efforts by Facebook to be more transparent about advertising on its site, it's not always easy to identify who is behind a political ad.

Which is why CBC News is teaming up with ProPublica, a U.S. non-profit news organization, to investigate political ads on Facebook.

But we need your help.

By installing a browser extension called Facebook Political Ad Collector developed by ProPublica, CBC readers can help journalists get a better picture of the scope of political ads that Facebook users across Canada are seeing.

How it works

The extension can be downloaded from either the Chrome Web Store or the Mozilla Add-ons Store and added to a Chrome or Firefox browser on your desktop or laptop computer. The tool won't work in other browsers such as Safari and Internet Explorer — or on mobile devices.

Once it's installed, each time a paid advertisement pops up in your news feed while you have Facebook open on a desktop or laptop, you'll be asked to classify the ad as political or not.

Once installed, the browser plug-in gives you the option to classify an ad as 'political' or 'normal' and also to see ads that other Facebook users have marked as political. (CBC)

An example of an ad that would be flagged as non-political in the ad collector tool, which was created by the U.S. news organization ProPublica. (CBC)

That information will be fed into a database of political ads that can be analyzed by CBC and other news organizations and help us dig up and research news stories.

The information in the database is crowdsourced, so the more people who use the extension, the more entries will appear in the database and the more news stories CBC will be able to tell.

The database will also include the targeting information that Facebook users see when they click on "Why am I seeing this?" under the three dots in the top right corner of sponsored posts.

Ads that users flag are collected in a database, above, that also includes the targeting information associated with the ad but no personal identifying information that would link the ad with the user who submitted it. (CBC)

Once you have the extension, you will also be able to see ads targeted at other Canadian users who have installed it — and who may fit a different political or demographic profile.

What the extension won't capture, however, are posts by partisan groups or individuals that might serve as de facto political content but are not paid advertisements per se. It only captures posts marked "sponsored."

How will CBC use the ad information collected?

CBC hopes the information gleaned from the political ads submitted by Facebook users will enhance our political and election coverage and generate story ideas of public interest.

The tool helped ProPublica expose political ads that were scams or malware and ads from the 2016 election campaigns of Donald Trump and Hillary Clinton that violated disclosure rules. The organization has made its crowdsourced database of U.S. political ads publicly accessible on its website.

In Australia, the Guardian newspaper found controversial ads using the ad collector during that country's referendum on same-sex marriage that may have violated campaign rules. The paper also posted the full database of collected ads online.

The New York Times used a similar type of crowdsourcing tool to monitor political ads on Facebook in the 2016 U.S. election, and developers in Britain used the same principle to create the Who Targets Me? extension during the 2017 U.K. election.

Ontario Premier Kathleen Wynne is one of several candidates in the June 7 provincial election who has been using Facebook to spread her political message. (Chris Young/Canadian Press)

In addition to CBC and the Globe and Mail in Canada, other media organizations that are using ProPublica's ad collector include: Italy's Openpolis; Die Republik in Switzerland; Der Spiegel, Suedeutsche Zeitung and Tagesschau in Germany; Dutch Public broadcasting; and Information in Denmark.

Protecting your privacy

Obviously, given recent controversies about Facebook data collection, we want to ensure your privacy is protected. The extension will not collect names, personal details or any other data that could be used to identify you.

Only information on paid ads is collected.

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"The tool does not collect any personally identifiable information, and will not learn which ads are shown to which user or which user voted on what ad," says ProPublica, which manages and controls the database.

What the tool collects:

Basic information about each ad, such as the Facebook ad identification number and the date the ad appeared in the system.

Targeting information that appears with the ad — criteria such as age and location that is used to determine which ads get shown to which users. This information is not connected to any data that could be used to identify a user.

What the tool does NOT collect:

Personally identifiable information from the collected ads, including Facebook ID numbers and tracking identifiers, or pixels, which can be used to identify users.

Names and profile links of the user's friends who have liked the ad and any comments on the ad.

Learn more about the tool

When you install the extension, you will be able to review ProPublica's terms of use before completing the installation. In the meantime, you can:

Watch the Facebook Political Ad Collector in action: