I can't find a way to google this answer, and I'm not sure what the best title for this question would be either. If you go to a video on facebook, such as https://www.facebook.com/sari.electronplus/videos/10208501562556645/
and you look at the source, there are all these lines with url's
{"type":"js","src":"https:\/\/www.facebook.com\/rsrc.php\/v3ixjD4\/yL\/l\/en_US\/WwzFPTYi5Xh.js?_nc_srcc=2665","crossOrigin":1},"CDaAd":
For what reason are there "/"s instead of "/" in the link?