Source: https://www.youtube.com/watch?v=mUIxKaUYY9g
This one played out mostly on Twitter, but I thought might be of interest to Skydentify members.
An impressive looking video of something streaking past a plane window turns out to be another plane (identified by @flarkey, again)
One interesting aspect of this is that the video owner (it was taken by her daughter) denied with was sped up. However looking at the replay of the ADS-B data in sitrec, it obviously is.