A response to the hackings.

It's not hard to use a proxy or maintain a different IP for each set of accounts you wish to keep separate.

Your arguments have been proven false by a literal pomegranate ton of cases. You act as if this is impossible to implement when numerous other companies have the systems already in place to deal with it. Fraud is a little more in your face than hacking. Hackers aren't making new mules each time they hack someone. They aren't changing IPs every time they steal an account. The patterns are very different for fraud and for legit hackings.

edit: static IP's are fairly common. Even if your ip isn't static, you generally get one of a small group of IPs each time you connect.