There’s a reason why you had difficulties accessing Sony’s online PlayStation store and Microsoft’s Xbox Live network during Christmas. Each has been experiencing disruptions from a DDoS attack that began on Christmas Eve, continued through Christmas Day, and is still ongoing.
The group that has claimed responsibility for the disruptions is the same one that has a history of destroying other people’s fun by making it impossible for them to access online games. This is especially problematic during Christmas as people who received new games try to get online to play them. Some have noted that Sony’s decision to let people download the controversial movie The Interview through Xbox Video could be adding to the problem.
The PlayStation Knowledge Center has mentioned the issue. At the time I am writing this, the PSN Status is “Offline”. Further information says: “We are aware that some users are experiencing difficulty logging into the PSN. We will update this article with any changes that occur in regards to this issue. Thank you for your patience.”
Similarly, Microsoft has posted some information about the outage on their Xbox Live Support page. At the time I am writing this, the Xbox Live Core Services is “Limited”. Further information says: “Xbox members, are you experiencing issues when attempting to sign in? We’re aware of this issue, and we’re working to find a fix ASAP! We appreciate your patience in the meantime, and we encourage you to retry signing in when you get a chance. We’ll update you as soon as we know more”.