Profiting from those who apply rules blindly

A headline in my Telegraph news feed caught my attention this evening:

Two investors in Reed Elsevier have sold their shares as a protest that the publishing giant runs arms fairs

It appears that Reed's activities fall foul of the Joseph Rowntree Trust's "ethical" rules.

Naive implementations of index trackers are susceptible when the make-up of the fund changes: everybody knows the managers will be selling the stocks that have been dropped and will be buying the stocks that have entered the index.

I wonder if anybody routinely profits from anticipating the behaviour of funds, such as this Rowntree one, that are constrained in some other way? It probably wouldn't be too hard to keep tabs on companies assumed to be "ethical" or "green" or whatever and track any news stories about them for signs that their right to claim such a designation has been forfeited.  On the assumption that some holders of such companies may be forced to sell, there has to be an opportunity in there somewhere!