Windfall Profits Tax - arbitrary and discriminatory

Some Commentators are toying with the idea of imposing a windfall profits tax on British Banks. We are not trying to defend what some may consider the indefensible but a few caveats merit consideration: if British Banks are to be taxed then all banks in the UK would have to be taxed. How would it affect the foreign banks with large operations in the UK? If they are not taxed this would distort competition. Banks such as Barclays and HSBC would also have every incentive to relocate to tax-friendlier regimes. And most importantly: in this age of heightened awareness of 'human rights' - how can a special tax on a single industry be justified? if a discriminatory tax such as a windfall tax on banks is imposed it would clearly be the duty of the bank's managements to take this case to the relevant Courts - in particular the European Court of Human Rights. And if banks can be taxed at will, what about football players, entertainers, lawyers and anyone else who one day catches the attention of freely-spending politicians?