public class AutomaticDecompressionWebClient : WebClient
{
    protected override WebRequest GetWebRequest(Uri address)
    {
        var request = base.GetWebRequest(address) as HttpWebRequest;
        if (request == null) throw new InvalidOperationException("You cannot use this WebClient implementation with an address that is not an http uri.");
        request.AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip;
        return request;
    }
}