Every player in the game has a limited number of available Raid attempts per day. However, you can encounter a situation when a player Raids your Castle over the established limit and sends many consistent attacks. This can be done without any cheats, hacks, or tricks.
The thing is that when you reach the limit of available Raid attempts, you will still be able to Raid other Castles. However, the Raids you send over the limit will be sent as regular attacks. This means that the troops will attack your opponent's Castle and fight with the enemy's troops, but if the Raid is successful, they will not bring you plundered resources.
Multiple successive attacks are considered normal game processes and do not violate the regular gameplay rules. You can always protect your Castle using the Weor's Protection item or defend it with your troops or reinforcements.