I doubt very much that illegal miners would expend there time...

I doubt very much that illegal miners would expend there time and energy to steal pegmatite. Firstly, unlike gold or copper, it would be impossible for them to roughly refine pegmatite into a lithium concentrate. Further consider the huge quantities of material they would have to move, whilst remaining undetected. Secondly, who would the illegal miners sell the raw material to, there's no local market for pegmatite and the commodity is usually sold in bulk via offtake contracts to battery manufacturers overseas.

Do your own research and GLTA