UPDATE: Electronic Arts told Polygon it has "no reason to believe there has been any intrusion into our Origin database" at this time, though that doesn't negate these odd reports. The original story follows.
Unusually large numbers of Origin accounts are getting hijacked, according to threads on NeoGAF and Electronic Arts' own forums. Affected users report finding change-of-address notifications in their inboxes, and sometimes even changed passwords when they attempt to log in.
Eurogamer reports one of its own writers found his account's email address changed without solicitation. Upon contacting EA customer support, the service representative was unaware of any problems but offered to "escalate" the report.
EA has since responded to Eurogamer with what appears to be a generic service issue message: "For any customer who cannot access their Origin account for any reason, we ask them to please contact Origin Help or EA's customer experience group at help.ea.com."
Several users have indicated their support process stalled because their provided date of birth did not match those in Origin's records--indicating either mass amnesia or hackers changing said details to slow customer support action.
While account hacking is an ongoing issue for many online services, the glut of recent reports describing similar circumstances should be cause for concern. It might not be a bad idea to pop onto your Origin account and give it a fresh, unique password--though there's no guarantee that will plug whatever security gap is being exploited here.