@MeEtc:
This is exactly what I'm doing right now, but I was wondering if there were an easier solution, maybe using some kind of event handler for display picture changing.
@SpunkyLoveMuff:
The file names are the originals from Messenger. Even if the picture is updated by the user (or by another script), the file name won't change, whereas if you compare the bytes, it is very unlikely that two different images have the same size.
/edit:
It was very strange for me to find event handlers for just every kind of user information change, but not for the display picture...
/ 
