This law officially phrohibits smoking in public places such as bars, restaurants and coffeeshops. This law is designed to prevent the effects of second-hand smoking. Currently this law is not upholded. You can smoke in most coffeeshops, bars, restaurants and cafes. Until 2009 you can almost smoke freely everywhere, in 2009 there will be a non smoking law everywhere. If this law will apply for coffeeshops, is yet unknown.
Also there is a new banning of public smoking of marijuana in some areas in Amsterdam. The goverment hung a sign that shows that it is illegal to smoke marijuana there. Multiple coffeeshops had a reward if they got the sign from someone. This sign was stolen within the first day. After a few weeks it was stolen numerous times, so the goverment decided to make the sign sellable on the internet. So people could buy it on the internet and thus preventing it from being stolen.