Millions of Americans are being sandbagged yet again by consequences arising from the banking crisis. For the last six months or so, lenders have been wrecking havoc on many of their customers by reducing credit limits , increasing prevailing interest rates , or both. These unilateral moves have been made by credit card companies, which are virtually unregulated, and by lenders who have extended other revolving credit such as home equity lines (HELOCs.) To a certain extent this is not new. Credit...