This law review article is from 2008. In it, the author explains why a call records retention program of the sort that has now been disclosed would be an unconstitutional violation of the First Amendment Right to Freedom of Association. Recent controversies about the National Security Agency's warrantless wiretapping of international calls have overshadowed equally disturbing allegations that the government has acquired access to a huge database of domestic call traffic data, revealing information about times, dates, and numbers called. Although communication content traditionally has been the primary focus of concern about overreaching government surveillance, law enforcement officials are increasingly interested in using sophisticated computer analysis of noncontent traffic data to map networks of associations. Despite the rising importance of digitally mediated association, current Fourth Amendment and statutory schemes provide only weak checks on government. The potential to chill association through overreaching relational surveillance is great. This Article argues that the First Amendment's freedom of association guarantees can and do provide a proper framework for regulating relational surveillance and suggests how these guarantees might apply to particular forms of analysis of traffic data.
Quoting from the article: The First Amendment’s freedom of association guarantees require that any program of relational surveillance meet a strict scrutiny standard. The surveillance must serve a legitimate and compelling government interest and its methodology must be sufficiently accurate and narrowly tailored to that interest in light of the extent to which it is likely to expose protected expressive and intimate associations.
The collection of all meta-data for everyone all of the time is not "narrowly tailored" and hence it would fail strict scrutiny. The Government's program is unconstitutional. Freedom of Association in a Networked World: First Amendment Regulation of Relational Surveillance by Katherine J. Strandburg :: SSRN | 
