The Canadian banks are now on credit watch from Moody's due to the housing bubble...
'The rating agency is now reviewing the banks because they “face challenges not fully captured in their current ratings,” including concerns about consumer debt levels, housing prices, macro-economic risks and the weight of their capital markets divisions within their business mix."
In layman's terms..the banks have leant too much to people well over their heads in debt, especially in the bubbly housing sector, and too much of the rest of their income comes from professional gambling departments ('Capital markets divisions')
The only one missing from the list was Royal Bank, as it has already been down-graded!