Why would any broker provide you margin capability if you don't want to be responsible for your loss?......
If they don't have a choice?......
The EU regulator for the industry, ESMA, has made negative equity protection mandatory for all EU forex brokers from August.
There has been talk that now that the risk of losing more than you deposited has been eliminated (and this protection will be backed up by the national regulators in the EU), someone somewhere in Europe is going to go all in on a crazy trade. It'll be interesting to see how it turns out.