A new report in Der Spiegel says the the United States has been spying on German Chancellor Angela Merkel since 2002, and a different report (albeit from a less reputable source) says President Obama knew about it.

When news broke earlier this week that the NSA has been spying on European leaders, including the cell phone of German Chancellor Angela Merkel, it created an uproar not seen since the end of the cold war. The Der Spiegel story shows just how comprehensive the NSA spying was: Beginning in 2002, Merkel's calls were either recorded or monitored by NSA officials. Germany has responded by sending its top intelligence officials to Washington to sort through this mess, while President Obama continues to claim he had no idea that the spying was happening. Or maybe he did.

According the the German tabloid Bild (think New York Post levels of credibility) Obama was briefed on the monitoring of Merkel in 2010 by NSA chief Keith Alexander. "Obama did not halt the operation but rather let it continue," an anonymous source within the NSA told Bild.

Even more troubling than Obama's possible knowledge of the spying, is that most of the monitoring was being done from within the US embassy in Berlin. Embassy or not, the spying operation would be illegal under German law. Germany's Interior Minister Hans-Peter Friedrich told Bild that those "responsible must be held accountable."

The NSA documents detailing the operation (given to Der Spiegel by former NSA analyst Edward Snowden) warned that any disclosure of the spying would amount to "severe damage for the US's relations with a foreign government." It has.