Are PSN servers down?

I was playing mw3 on my ps3 a few days ago and I couldn't sign in for some reason so I turned my router and playstation off and turned back on and it worked. It's been doing this for a couple of days so I thought there was a problem with my router, now I just can't sign in at all and I've tried turning off my router and ps3 several times but it's just not working. Some people online have said the servers are down but some are saying Sony said everything should be working fine. Does anyone know if it's actually down and when/if it'll be back up? Thanks for any feedback