have mirc ask for social security numbers

That would be meaningless. Why? Because anyone can put a number(s) in the space provided and press return. You'd need a name and number or two numbers which can then be verified against a government database. Now comes the good part - Privacy legislation - Not all countries have it but some do and those governments arn't going to surrender personal information held by them for the purposes of keeping the occasional paedophile out of chat rooms.

The last thing is, not every country has a social security numbering system. What do people outside the US use? The only time I ever had the equivalent of a social security number is when I was briefly on the dole about 15 years ago.