public boolean removeUserSubscription(String email, final long blogId) {
email = TextTools.cleanJID(email);
DataManager dm = DataManagerFactory.getInstance();
PersistenceManager pm = dm.newPersistenceManager();
Query qUser = pm.newQuery(User.class);
qUser.setFilter("id == email");
qUser.declareParameters("String email");
qUser.setRange(0, 1);