def isPrivate(urlPath, repos):
    """Check if a URL is a private URL

    >>> isPrivate('/downloads/me/', None)
    True
    >>> isPrivate('/downloads/me/', [])
    False
    >>> isPrivate('/downloads/me/', ['me'])
    True
    >>> isPrivate('/repos/me/', ['me'])
    True
    >>> isPrivate('/downloads/me/', ['unknown'])
    False
    >>> isPrivate('/somewhere/me/', ['me'])
    False
    """
    # If provided check whitelist of Github repos in the format
    # "<userororg>/<repo>", for either API v3 or static downloads
    if repos is None:
        # for backward compatibility all repos are private if there is no
        # "github-repos" entry in the buildout section.
        return True
    # now check the whitelist
    for repo in repos:
        if not repo:
            # ignore empty entries
            continue
        api_repo = "/repos/%s/" % (repo,)
        dl_repo = "/downloads/%s/" % (repo,)
        if api_repo in urlPath or dl_repo in urlPath:
            return True
    return False