Huge Filenames - Where do they come from?

[Nshowalter]

I have ended up with several images in my catalog with huge filenames such as this: 17632279_10107694503724751_6250391958677724408_o.jpg

I have a feeling it happens with syncing from LR desktop but I'm just not sure. Anyone have an answer?

Nic

[Conrad_C]

The format (three long numbers, the first one much shorter, delimited by underscores, with a single letter at the end) looks similar to filenames of images stored on Meta services (Facebook, Instagram). Is there any chance those images are known to be downloaded from a social media account of some kind?