Cheating ruins everything. Cheating makes game play unfair for others who may be truly competitive and strategic. Cheating makes others disrespect and un-friend you. There can be unforeseen consequences, like getting viruses, trojans or your account hacked from downloading a cheat/bot program. And you will get banned from the game for violating terms of service.
Zynga has released this statement:
Because we want to keep our games fair and our players safe, we want you to be aware of the following:
The use of "Bot" Programs or 3rd party scripts that automatically perform actions on your computer, whether in a game or on a website, is strictly prohibited. Please read Zynga's Terms of Service. In addition to the possibility of having your account suspended, some Bot programs or scripts that you get from someone else can contain Trojans or Viruses. If you use or have used a Bot program in the past, you could find your password, User ID and other private information have been stolen.
So play fair and keep safe. Don't download Bots or use them!
From Zynga help center.