The answer is simply 'No'. But at the same time, there exist lot of legal complicacy. The situation needs to be studied in detail. The circumstances under which it was accessed can validate the legality of such accessing. Police is also a human being and they too cheat people. Sometime they work without any official authority. So, if any situations like accessing ebay accounts by the police (or anybody else) without any requisite warrant occur, it need to be investigated thoroughly, on which circumstances they were forced to access your ebay account. The act is a gross violation of human rights.
For accessing the ebay account one has to know the user id and password, which is secret information. Nobody (except the user), even not the administrator, is supposed to access them. For accessing these ebay accounts by the police, there should be sufficient reason substantiated by the court warrant. Equipped with all the legal tools, police may approach the ebay authority for disclosing and accessing the particular account. The authority in turn is bound to inform you about the breach of security that had taken place. They may take you into confidence or not, that is their wish depending upon the gravity of the situation (read your account balance!).
For accessing the ebay account one has to know the user id and password, which is secret information. Nobody (except the user), even not the administrator, is supposed to access them. For accessing these ebay accounts by the police, there should be sufficient reason substantiated by the court warrant. Equipped with all the legal tools, police may approach the ebay authority for disclosing and accessing the particular account. The authority in turn is bound to inform you about the breach of security that had taken place. They may take you into confidence or not, that is their wish depending upon the gravity of the situation (read your account balance!).