Individual countries could threaten add alternative currencies/payment systems, subject to capital and exchange rate controls, in parallel to the Euro and just ignore any protests. They should actually set in motion the process with public discussion on the design of the currencies, etc. Were they to call them Franc, Lira, Peso, Drachma it would make the message clear: the ECB is allowing 25%+ unemployment and deflation in much of the EuroZone so we are going to do something about it.

"It is not necessary to have hope in order to persevere."