Alliances are usually responsible for the conduct of their members

Ask politely,  Little Empire Mojo  without threatening. If you make empty threats, they may be recognized and probably result in further attacks.

If the attacker is a member of an honorable alliance, speak with the chancellor of that alliance. Alliances are usually responsible for the conduct of their members. Buy Little Empire Mojo  Again, be polite.cheap KOC gems

If they are from a dishonorable alliance or are persistently farming you and won't stop, then the are a few things to do to annoy them greatly and should stop them:

Hide your troops in sanctuary - in the castle
Keep resource levels below storehouse levels.  Cheap Little Empire Mojo  A level 10 storehouse with level 10 shrinking powder keeps 2 million of each resource safe, Cheap Little Empire Mojo  excluding gold.buy cheap KOC gems