If you are running Facebook Ads, you must know about the Facebook Ads Library.  If you ask Facebook the purpose of it, you will find that transparency is the most important.  The Ad Library is a place where you can search for ads that are running across Facebook Products. You can use it to get information about the ads you see.  For all ads, you can search for ads that are currently active on the Facebook Products.  For ads that are about issues, elections or politics, you can also search ads that are inactive (no longer running across Facebook Products). Transparency is a priority for Facebook to help prevent interference in elections, so the Ad Library also shows you additional information about these ads, such as who funded the ad, a range of how much they spent, and the reach of the ad across multiple demographics.  Facebook stores these ads in the library for 7 years.

You can view and use the Ad Library at https://www.facebook.com/ads/library

One thing I really do appreciate is that Facebook will check into something being “real” vs. “fake”.  Especially during COVID-19.  And why people would put money towards ads about fake cures for COVID need to find something better to do with their time, like seriously!