Question juridique clé
Whether X. had standing to challenge the mutual legal assistance measures, including on behalf of the dissolved companies and Y.
Solution extraite
His standing could be left open for his own claims, but he was not entitled to raise arguments on behalf of third persons or third-party companies.
Motifs extraits
The court found that complaints for third parties are inadmissible; as to X.'s own standing, the issue did not need final resolution because the appeal failed on the merits.