If it's the "Wanted Dead or Alive" type, these are generally frowned upon, but if there is good reason (bike theft for instance) people here generally have an open mind and it might be allowed.
If it's a physical item or service, which doesn't involve stolen goods, exchanges of bodily fluids, slavery, assassinations or violence, then generally they get put in the bike parts for sale section and are titled with "WANTED : xyz" .
The previously mentioned "exchanges of bodily fluids, slavery, assassinations or violence" should be listed in the Lounge.