private void HashtagClickedInTweet(object sender, RoutedEventArgs reArgs)
{
    if (reArgs.OriginalSource is System.Windows.Documents.Hyperlink)
    {
        Hyperlink h = reArgs.OriginalSource as Hyperlink;

        string hashtag = h.Tag.ToString();
        string hashtagUrl = String.Format(Settings.Default.HashtagUrl, Uri.EscapeDataString(hashtag));

        try
        {
            System.Diagnostics.Process.Start(hashtagUrl);
        }
        catch
        {
            // TODO: Warn the user? Log the error? Do nothing since Witty itself is not affected?
        }

        reArgs.Handled = true;
    }
}