Really? They run it to a bong? How are they going to get a buzz off of that?
Yes, yes, I knew you meant bung but I couldn't help myself.
At any rate, to answer your question; "No you can't." The reason is that most weber intakes are individual runners and a Positive Crankcase Ventilation system works off of manifold vacuum. So if you try to plumb a PCV valve into an individual runner, not only will the vacuum be intermittent but then that one cylinder will have what amounts to a huge vacuum leak.
If, however, if you want to go to a crankcase evacuation system then that would be relatively easy but also possibly ugly as the hoses from your VCs should run to fittings with anti-reversion valves at the header collector. Like this:
Hope that helps man.