Can we add other sites/mylots link to the post?

I don't have much idea about it but the thing is clear to me that they delete your discussion if in it any link is given.As this happened to my post that a person posted some link in my discussion and then in some days it got deleted.I feel it is a bit of unfair that they delete the whole discussion,actually they should only delete the post the person had made instead of the whole discussion.