Some minnows in there , swimming in a vast ocean of finance , mortgages and debt .................

http://www.bsa.org.uk/aboutus/buildsocmember.htm

I wonder how many of these you can still carpetbag?

Very few I suspect. Most make you sign a covenant when you join. As for them swimming in a sea of debt, this is nowhere near what the banks are. The limit which building societies can borrow on the market is 30%. Personally I don't want to see any go under and hope that none of the smaller local or regional ones have to merge to survive. I don't give a toss about the demutualised ones, they can go bust IMO.