Northern Rock are a very big bank (based 10mins drive from my house) but most of their business is just mortgages. The money they lend out comes mostly from the international money lenders.
Because of the trouble in the USA no-one is lending money. So Northern Rock asked the Bank of England if they could borrow money from them instead
if they feel they need it.
This is how this bank works an in no way reflects any problems with the bank.
However people panic as they do. Including investors.
So now the share price has gone down 30% leaving the bank open to hostile take-over bids. That could mean job losses in my town if that happened.
Plus the bank sponsors Newcastle's Soccer team, Rugby team and (I think) Durham Cricket team. So we don't want to loose that!
All because of peoples lack of understanding of how the bank works.
Personally I don't like Northern Rock anyway. The Nationwide Building Society is MUCH better.