// debug is never used.
// Wouldn't have been better to use and return a checked List interface instead of uncheck implementations ?
// Are we sure we return the OFFLINE user devices here ?
public LinkedList getOfflineDevicesForUser(User user, boolean debug) {

    // Why not using the LinkedList implementation directly ?
    ArrayList l = new ArrayList();

    // Why to use an unchecked List instead of List<Device> ?
    // Isn't there any conventions to use the i, j, k suite for counter variables instead of x, y, z ?
    // Couldn't we replace that block with a: for each / if ? removing the need of the found variable.
    List allDevices = deviceRepository.getAll();

    for (int x=0; x<allDevices.size();x++) {

        // Why a primitive should be initialized to its default value ?
        boolean found = false;

        // Why to use an unchecked List instead of either List<User> or List<Owner> and then cast it down to List<User> ?
        List owners = ((Device) allDevices.get(x)).getOwners();

        if (owners.size() > 0) {

            for (int y = 0; y < owners.size(); y++) {

                User owner = (User) owners.get(x);

                found = (owner == user);

            }

            if (found && allDevices != null)

                l.add(allDevices.get(x));

        }

    }

    return new LinkedList(l);

    //What do you think about something like this ?

    /*
    public List<Device> getOfflineDevicesForUser(User user) {
        List<Device> userOffLineDevices = new LinkedList<Device>();

        for (Device device : deviceRepository.getAll()) {
            List<User> owners = (List<User>)(List<?>) device.getOwners();

            // TODO: Also check the device is offline ?
            if (owners.contains(user)) {
                userOffLineDevices.add(device);
            }
        }

        return userOffLineDevices;
    }
    */
}