They are sub-tenants in breach of House Rules, BL and PL. You are entitled to appropriate levels of quiet. You can request that the Board file a 'Notice to Cure'/30 day to begin foreclosure proceedings be filed against the shareholder. You can request that the sublease be terminated or not be renewed due to repeated breach of the sublease requirements which should be requiring strict adherence to the Coop's rules. You must start and keep a paper trail of everything, in writing both to the Board, and the shareholder who is accountable for the actions of his sub-tenants, and file complaints with the local police precinct. Yes, if they are foolish they will retaliate, which should provide further evidence of the breach. Good luck, noise is probably the biggest complaint that Boards and Police have to deal with I think. Dogs I think are #2. Document everything, time of day, date and specifics, everything, nothing is too small if you are collecting on a consistent pattern of abuse.