When you delete a topic wouldn't it be better to tell the guy that made the topic ( on P.M or something ) why you deleted his topic ?

P.S.: I don't want to make the moderators angry at me ...it`s just a suggestion !!

Please could you read the rules on directing questions to moderators.

"Posts may be deleted for any reasons the forum administrators deem reasonable.
Users may not argue a moderators decision publicly. Any and all complaints directed at a moderator must first address the moderator in question via PM. If the problem can not be resolved, then the moderator and user must send their positions to the forum admin. The forum admin will make or change any and/or all final decisions."

Moderators in most cases contact the users when a thread is deleted. Unless the reason is obvious.

If you have any further questions, or would like to discuss the matter further, giving me more information on the thread deleted please pm me.