Is there any anti-spam laws? and if there is why there's still spam?
Is there any better filters to stop spammers?
Yes there are anti-spam laws. In America there should be some Spam Laws. The reason why there is Spam is due to the Reason that not every Land has Spam Laws. For some Countries Spam is not bad. But most Spammer come from Asian Countries and USA.
... and i think if the people stil click/open it there will a spam and spam and spam and it will never end... !
But only if they buy the Product which was advertised in the Spam. Without buying the Product there would be no Spam.