ProPublica is doing an investigation into political ads on Facebook. If you use that platform and use Chrome or Firefox, you can download an extension that will scrape ads from your newsfeed, identify which ones are political, and recorded in a database.
Political ads on Facebook have come under scrutiny since it was revealed that Russia used such messages to try to influence the 2016 U.S. election. But online political ads are often seen only by a small target audience — making it difficult for the public to check them for accuracy. In order to shine a light on political advertising on Facebook, we built a tool that allows Facebook users to automatically send us the political ads that were displayed on their news feeds. (You can install the tool, known as a web browser extension, for Chrome or Firefox.)