The Gatwick Airport drone incident from 19-21 December 2018 involved "67 reports of drone sightings close to the runway" (Wikipedia).
Regardless, I haven't found any photos or videos of the drones. Are there any? If not, why not? Were they too small (or far away) to be seen by a cellphone camera? But then how could humans see them? How can 67 people see a drone in this day and age and none of them record it? Is it plausible that there actually were no drones?