I think your focus is wrong, as pwim said you should focus on creating a benefot to multipl eusers rather than account sharing. by going after, what you refer t

I think your focus is wrong, as pwim said you should focus on creating a benefot to multipl eusers rather than account sharing. by going after, what you refer to as "cheaters" means making an enemy of your customer, however if you view them as a customer whose needs are not being met you could increase overall subscription rates by focussing on these benefits. I suggest continuign to try and track your "cheaters" but approach them to discuss why they do it and how multiple accounts would suit them better e.g. easier to communicate with other users ont he same platform as you can track messaging by username, if 10 people use the same login then mo one know who is sending or responding to messages within the system.