Readers will likely recall that the German Federal Constitutional Court earlier this month held unconstitutional a German law requiring the retention of certain telecommunication data (German decision here, German press reports in English here and here). The law that was invalidated transposed Directive 2006/24/EC, passed largely in response to the Madrid and London bombings, into national law.
Ireland had already unsuccessfully challenged that Directive, passed under the first pillar (internal market) rather than the third (police and judicial cooperation in criminal matters), before the European Court of Justice (ECJ)(C-301/06 Ireland v. Council and European Parliament, Judgment of Feb 10, 2009).
As reported here, the EU Commission is now taking another look at the Directive. Incidentally, the new Commissioner for Home Affairs is from Sweden; having resisted transformation of the Directive into national law, the ECJ recently found that Sweden failed to fulfill its obligations (C-185/09 European Commission v. Sweden, Judgment of Feb 4, 2010).
Austria prepared a national law intended to transpose the Directive but hesitated to pass it, citing concerns regarding its constitutionality. Courts in Bulgaria and Romania previously declared the respective national laws implementing the Directive unconstitutional.