403. That’s an error.
Your client does not have permission to get URL /videoplayback?requiressl=yes&shardbypass=yes&cmbypass=yes&id=a6d8fb3532b404c5&itag=18&source=picasa&cmo=secure_transport=yes&ip=0.0.0.0&ipbits=0&expire=1431909435&sparams=requiressl,shardbypass,cmbypass,id,itag,source,ip
from this server. That’s all we know.