'Officially' you can't smoke tobacco in coffeeshops, only pure joints (only cannabis) or hasheesh from a pipe. Yet you can roll a joint with tobacco in a coffeeshop and smoke it elsewhere.
If the selling counter is covered with glass and airconditioned, you can smoke whatever you want, because the law is basically to protect the people working in bars, cafe's, hotels and restaurants, the sector to which coffeeshops belong as well.
But there is more: if you light a prerolled joint (with tobacco) in a coffeeshop, noone can make you open it to check if there is tobacco in it, so they just let you smoke it. If you roll a joint with tobacco and light it, some official must have seen both the rolling part and the lighting part too write out a fine to the coffeeshop if they don't do anything about it.
To ban smoking cannabis in coffeeshops they would first have to legalize it, because right now it is a 'controlled substance' that is 'decriminalized', which pretty much means the police publicly declared they won't do anything about people smoking it or coffeeshops selling it (buying it from growers is, however, still illegal). So technically the use of cannabis was never legal, the police just turned a blind eye.
All in all it is a pretty paradoxical situation, where noone really knows yet what the long-term effects will be, because it is also not clear yet how this new law will be enforced.
