Java moss pruning

["Pete" <peteal at sympatico_ca>]

Hello, I got some nice rock dens I created that are now coated with java
moss.  My question is, is there any way to prune/mow it?  The moss is
getting pretty long now and I don't know how much (if it stops at all)
longer it's going to grow.  Starting to look pretty shaggy right now and
looking more like a giant fuzz ball as opposed to a rock den covered with
fur :)

Thanks
Pete.