NEW DELHI: The Supreme Court today refused to expedite the hearing of Aadhaar cases challenging the constitutional validity of the scheme but observed that data collection by private agencies is not a good idea.A bench headed by Chief Justice J S Khehar made the remarks after senior advocate Shyam Divan sought urgent hearing of the plea citing privacy concern."We are not inclined to give immediate hearing as there are limited resources but biometric data collection by private agencies is not a great idea," the bench also comprising Justices N V Ramana and D Y Chandrachud said.Divan, who represented one of the petitioners, said that these matters needs urgent hearing as there is individual's privacy concern as biometric datas are being collected by private agencies.The apex court had on October 15, 2015 lifted its earlier restrictions and permitted voluntary use of Aadhaar cards in welfare schemes that also included MGNREGA, all pension schemes and provident fund, besides ambitious flagship programmes like 'Pradhan Mantri Jan Dhan Yojna' of the NDA government.The social welfare schemes, aimed at reaching the door steps of the "poorest of the poor", were in addition to LPG and PDS schemes in which the apex court had allowed the voluntary use of Aadhaar cards.A five-judge constitution bench had put a caveat in its interim order for the Centre and said that Aadhaar card scheme is purely voluntary and not mandatory till the matter is finally decided by this court, this way or the other way.It had said that that a larger bench was required to be set up for final disposal of the petitions that also include the question as to whether the right to privacy is fundamental right.A three-judge bench had on August 11, 2015 referred a batch of petitions, challenging the Aadhaar card scheme, to a larger bench for an authoritative view on the question as to whether the right to privacy is fundamental right or not and had also restricted the use of Aadhaar to PDS and LPG scheme only.UIDAI, established by UPA-2 in 2009, issues Aadhaar cards to the citizens.Under the programme, every citizen is to be provided a 12-digit unique identification number for which biometric information is collected.