The Multiple Chicken Coop Cheat in FarmVille is no longer available. Zynga fixed the glitch in a an update made on December 10 that previously allowed this trick to work and now you should not be able to have more than one coop even if you try the trick.
For those that had multiple Chicken Coops before December 10, you may still have them, but it is no longer possible for those that tried after this date. So yes, it is possible that some people still have multiple coops. However, those that have multiple coops should be notified of risks involved in having them.
Risk of Multiple Chicken Coops:
* Those who have multiple chicken coops may risk losing their FarmVille accounts as it violates Zynga's user agreement. Some users who have submitted their farms for official Zynga contests have unknowingly exposed themselves by making Zynga aware of their multiple chicken coops which resulted in their forum accounts being banned or deactivated.
* If your second coops are deleted then you risk losing all the chickens that reside in that coop. (Unconfirmed: Currently we do not have any proof that this happened)