Responding to an earlier report, Apple sait it had never worked with the U.S. National Security Agency and that it was unaware of efforts to target its smartphones. Germany's Der Spiegel magazine on Sunday reported that NSA makes specialized gear and software to infiltrate and monitor computing devices, including mobile phones.

The report described a software (trojan) that allows infiltrators to push and pull and retrieve data from iPhones such as contact lists. The report did not suggest that Apple had cooperated with the U.S. spying agency on so-called backdoors. However, Apple issued the following statement:

"Apple has never worked with the NSA to create a backdoor in any of our products, including iPhone. Additionally, we have been unaware of this alleged NSA program targeting our products," Apple said in a statement.

"We will continue to use our resources to stay ahead of malicious hackers and defend our customers from security attacks, regardless of who's behind them."

In a statement, the NSA did not deny the spying, and it said any activities it undertakes are limited to foreigners.

"The United States pursues its intelligence mission with care to ensure that innocent users of those same technologies are not affected," NSA said.

The Der Spiegel report also said the NSA has penetrated products from U.S. technology companies including Cisco Systems, Dell, Huawei, Juniper, Maxtor, Samsung, Seagate, and Western Digital, among others. Cisco Systems and Dell. Cisco issued a statement on Dec. 29 saying that it?s "deeply concerned" about the government agency's attempts to exploit technical weaknesses in its products to gather electronic communication data.