Xbox Live users may notice issues when trying to use the service on Xbox 360. According to the XBL Status page, usage is limited for downloading purchased items, joining other Xbox Live members in online games and there are matchmaking and Smartglass application issues as well. Folks are also having difficulty signing into Xbox Live. Microsoft is on the case now, so hopefully all issues will be resolved soon. In the meantime, keep an eye on the official status page.
It's been working fine over here in leeds UK been doing GTA V heist last night with no problems. Send from space...