Ask Rabbi LJ -- Odd Halachic Question

OK, so WFNX has "King Without a Crown" by Matisyahu on pretty heavy rotation for the past couple of weeks. On Friday, when Julie Kramer played it, she pondered in passing whether marijuana was at all popular within the Chassidic community. I did a brief search, but other than finding references to a teshuvah by R. Moshe Feinstein, I couldn't find much.

So, I ask...is there any Chassidic rabbi who has ruled on the use of marijuana?