A change will be going out soon to fix the messaging. For the remainder of the day the message will read something like this (language localization per game of course).
This Viking is already under a barrage of Axe Slaps. They can only be targeted once every 4 hours.
Starting tomorrow it will give you a better indication of when this player will be eligible for you to invite your friends to punch/etc.
This Viking is already under a barrage of Axe Slaps. You will be able to invite your friends and Chieftains again in 3 hours.