Trackers can allow MPs to target campaign ads to website visitors without their knowledge
Overall, CBC News found that 99 MPs have advertising trackers on their websites. The CBC identified 98 of them through Ghostery, an online tool that allows users to detect trackers.
CBC News found that New Democratic Party MPs had far more trackers attached to their websites than MPs from other parties, including more advertising trackers. Most NDP MPs also deployed a similar selection of trackers.
Liberal MPs generally had the fewest trackers and the one or two trackers on the sites of most Liberal MPs are usually used for site analytics.
Conservative MPs employed a wide variety of trackers, including advertising trackers.