1 PROTECTION OF PRIVACY AND PERSONAL DATA IN EUROPEAN UNION LAW WITH REGARDS TO DATA RETENTION ABSTRACT The thesis deals with the issue of data retention, i.e. the issue of storing communications metadata by telecommunications service providers for the purpose of possible later access to this data by state authorities. The thesis focuses not only on the relevant EU legislation, but also on the related case law of the Court of Justice, which plays crucial role in determining the standard of protection offered by EU law. This analysis focuses on two main legal issues - the issue of scope of the EU legislation in this area and the issue of proportionality. With regards to the first issue, the author is of the opinion that the Court of Justice interprets the scope of the relevant EU legislation overly broadly. Author criticizes the fact that the Court of Justice applied secondary law adopted on the basis of Article 95 TEC on the issue of access to the retained data by the Member States authorities, including the authorities of Member States which are active in the field of national security. Regarding the issue of proportionality, author criticizes the fact that the Court of Justice perceives the blanket retention of communications metadata to be incompatible with EU law as such, no matter how strict the...