prevent password (account) sharing

[Ruth]

Could someone help me with this hack please, i am trying to prevent password sharing in vB, the hack is based on:

(a) limiting access to a specific account per one ip adress at the same time.

(b) if there are more than one ip adress, for the same account at the same time, the account will be reported to the administrator.

(c) limiting access to one account to a number of ips/day, for example if the there are more than 10 ips/account/day the account is reported &/or deleted.

Thanks