This type of activity should not be viewed, a priori, as a bailout of the banks. Arguably, it is an efficient solution from society’s perspective to a potentially costly deviation from the first best world of complete markets. Central banks, by virtue of their ability to create money, are uniquely placed to deal with such situations.
The alternative solution is for the private financial sector to self-insure fully against liquidity problems. If the objective is to maximise the welfare of the community – as it should be – it is far from clear that full self-insurance is the right policy.