The Supreme Court, which has been hearing a clutch of petitions challenging the constitutional validity of Aadhaar and its mandatory seeding to avail of government benefits, on Wednesday questioned the Centre over its decision to link the UID with mobile phone numbers. Citing a February 17 order in the Lokniti Foundation case, a five-judge Supreme Court bench, headed by Chief Justice of India Dipak Misra, said it had only asked if users should be verified in the interest of national security. The hearing, which began on January 17, has seen the apex court flagging a range of issues over data security and citizen profiling while the government has tried to defend the scheme, saying Aadhaar data was fortified by 10-metre-high and 4-metre-wide walls. The clutch of petitions have been clubbed with the first petition challenging Aadhaar, which was filed by former High Court Judge Justice KS Puttaswamy in 2012. He had argued that Aadhaar violated the right to privacy and had no legislative backing. The Aadhaar case comes on the backdrop of a nine-judge Constitution bench, headed by then Chief Justice of India JS Khehar, ruling last year that privacy was a fundamental right guaranteed under the Constitution.