I was on Europa for a while, and saw tons of these guys bouncing around umbra. Recalling into safe mining spots, mining, recalling out. It was so damn frustrating that I could do nothing about it except bagball their recall spots - which only works for a couple hours.
I could have lured up a monster from the wilderness, but it would probably have gotten gwacked. So I didn't bother.
On siege, you can take matters into your own hands. I love siege.