I guess it was mentioned over the weekend that chaff is getting nerfed :-(
"Chaff is too powerful: Chaff launcher capacity is being reduced (and the munitions is being made more expensive). Like a few other modules that use resources, our initial numbers managed to get out of line with other module balancing passes."
http://www.reddit.com/r/EliteDanger..._designer_on_changes_to_interdictions_a_nerf/
(Not sure where to find this on the official forums)