using System;

using System.Text.RegularExpressions;

using System.Linq;

public class Program

{

    public const string RegexMatchWWWLinks = @"((?=http:\/\/|www\.|https:\/\/)[^\s]+)";

    public static void Main()

    {

        string text = "Terve http://www.google.fi moi www.google.fi";

         var regex = new Regex(RegexMatchWWWLinks, RegexOptions.Compiled | RegexOptions.IgnoreCase);

            var matches = regex.Matches(text).Cast<Match>().Select(m => m.Value).ToList();

         var segments = regex.Split(text);

            foreach (var segment in segments)

            {

                if (matches.Contains(segment))

        Console.WriteLine(segment);

                else

                    Console.WriteLine("**** " + segment);

            }

    }

}