the ordinary man in the street has no idea of what so-called ordinary banks get up to. these banks all lend money to commercial businesses as well as private individuals like you and me. and the sums involved with commercial operations can be huge, thereby running the risk of huge losses. they mightn't get involved in dealing in commodities, trading, futures, foreign exchange transactions, etc., but can still lose as much money as an investment bank, as has been proved by hbos and northern rock.
the thing to remember is that whenever a bank lends money, there is an someone else who believes they can pay it back, whether that be a business or a private individual from his income. banks get blamed for the big losses they've sustained, and they're now getting blamed for not lending enough money. rock and a hard place....