This question already has an answer here:
We in the C# chat room are having an issue with people abusing stars. When someone starts spam-starring messages, we cancel the stars, but this gives the user their stars back, enabling them to spam us with more stars.
I think that stars should not be gotten back, so that someone who spams with stars can't use more than the daily limit.
Another possible solution I thought of is requiring the user to wait 15 or so seconds between stars. Even though that wouldn't stop the spam, it would make it more manageable.