I bet that Feeney / RAID and her ilk have been whispering in...

I bet that Feeney / RAID and her ilk have been whispering in ears for a long time about the "greedy mining companies" and how the Govt should taking a larger share of mining revenues.
A reflection of the dislike of mining and business in general from the left of the NGO spectrum.

Of course the good work that Anvil has been doing at a local level is irrelevant in their minds. It would meet some NGO's agendas if the Govt screwed down the return on current investments and stifled the incentive for further mining development.
And if the extra money gained "sticks" to the top of the food chain, rather than being spent directly on local communities, I doubt they care.

Its a shakedown, but probably not too bad, the Govt doesn't want to completely destroy confidence in investing in the DRC, but the damage to confidence in their legal system has already occurred.