We need to be sure that Quick Cache and Quick Cache Pro can only be "Network Activated" in a Multisite Network installation; because this is how Quick Cache is designed to work. WordPress makes this easy for us.
@raamdev (fellow WebShark) I'll submit a pull request shortly for your review.
See also: http://strangework.com/2013/06/14/how-to-create-a-network-only-plugin-in-wordpress/
Network Activate Only; see websharks/zencache#50
@raamdev Changes submitted for review. You should be able to close this now.
This enhancement was released with Quick Cache v131224: