Political advertising on social media is at risk of being lost forever
Not that long ago almost all political advertising was clearly visible in the physical world. Posters, newspaper ads and pamphlets were widely circulated, collected and preserved. It is not unlikely that you are able to walk into an antiquarian book shop and find examples of political propaganda hundreds of years old. Other copies will end up in attics, basements, shoeboxes and occasionally be donated to archives or sold on eBay. It was easier to see who said what and to whom....