def _is_in_group(user, group_names):
    """
    Returns True if a given user is a member of one or more groups.

    :param user: The User object
    :type user: django.User
    :param group_names: A list of group names
    :type group_names: list[str]
    :return: Returns True if the user is in at least one of the named groups
    :rtype: bool
    """
    return user.groups.filter(name__in=group_names).exists()