Brian,
It's an unfortunate reality that our political-economic system renders economic upheavals such as our current one ripe with opportunities for further consolidation of control - we can't seperate economic from socio-political - in the hands of the few.
My understanding - I apologise as I don't have any real data to support the belief, I think it's detailed in "The Corporation" but I'm not certain of that - is that during the oil crisis of the '70's, when American oil companies were making enormous profits ( 5 of the top 11 Fortune 500 companies in 1974, the first year of the embargo, were US Oil ) they were buying up businesses outside of the oil sector who's valuations were being diminished by the fuel shortage and the fall in consumer spending.
Ultimately, it is going to fall to the average citizen to make decisions as to where they put their investments ( in the case you've noted, that would mean not investing in the Bank of Ireland should the Carlyle deal go through ) and live with the very real ramifications of that principled stance.
Whether that can ever be a reality is not certain. My experience is that people have little tolerance for principled stances that impact their own lifestyles and not those of others.