LEGALLY photostatting book??!!

Today tutor told us a 'GOOD' news.She said there are limited copies of our text book in library and even in book store.So according to the copyright law,student can photostatting the text book LEGALLY!!!Funny,right??!!Whatever got enough copy or not，I have photostatted the text book in earlier time.Now I only can say is doing less illegal thing,haha^^I found something today.Actually there are few more students have photostatted the text book,but they spend more than $20 for each,I only spent $14.05.Tutor just told in class,if they want cheap price,then come to ask me...haha^^ I am getting popular because of this!!!