You should check out some Zygmunt Bauman on ethics, he spent a lot of his life trying to figure out what ethics might look like in a postmodern society where individuals are (essentially) free - he basically (I think) argues that ethical behaviour is behaviour in which we always take account of 'the other' - we have care for them as our starting point for deciding whether we should engage in a course of action - thus ethical behavior will quite often be about not doing, rather than just 'doing what I like' - and this also allows for judgement, responsibility, contextual differences. He has a rather minimalist and generalist approach, but I kind of like it - something is ethical if people act out of caring for others. That makes it social, not individual.

Some people take the concept of ethics a step further and suggest we actually need to codify it in some kind of social rules - Jurgen Habermas for example.

TBH The issues of freedom and ethics were never my main interest, but I just got so far into social theory a few years back - and there they were... recurring themes!

Cheers!