Thank you Greg and David for the good explanations on this matter. Now I am rethinking the whole 'let's put the new song on Soundcloud' thing. Although it would be pretty bad luck if some evil guy ever took interest on my songs it still is a possible scenario and it would be very unlikely if I ever get paid again (I once got 50€ for use of of one of my songs on an educational dvd presentation)for music stuff.
I thought that if I put my songs on Soundcloud it would somehow give my stuff some sort of copy right protection. Here is one site that has taken at least one of my songs and probably countless other people's songs on their web page without any thought of copy right or any kind of money and apparently use it in some kind of malware distribution scheme.
http://bigmp3.in/listen/malibu-mae-2-186339507
Thanks again guys for the good advice.

I visited the song stealing site again and I noticed that if you try to play a song it works but if try to download a song with a phone then it gives you suggestions to 'improve your phone' by downloading some probably malware app. I tried to DL my song for test purposes.