The NSA could probably identify anyone on the internet given enough time and resources. I think the point of this is to make mass surveillance difficult, so they'll only target people flagged as suspicious instead of everyone.
So, unless they already had decided to keep an eye on you, your traffic would probably have gone unnoticed. Switching to a VPN now or something would keep you relatively anonymous.
the XKeyScore slides are 5 years old. who knows what they can do now.