The Bounce Whip is an item players can use on when on their own plot that kicks out or jails players they target with it. This is typically used to remove unwanted players, however the rules of the server allow people to bounce whip anyone for any reason. If you feel like another player is harassing you by putting you in jail over and over, then remember the whip can only be used when you are on someone else's plot.
The exact way a bounce whip punishes players is as follows:
First Whip: Kicked off plot.
Second Whip: Jailed for 5 minutes.
Third Whip: Jailed for 15 minutes.
Fourth Whip: Jailed for 60 minutes.
These punishments are per player, which means getting whipped off one plot won't give you a 5 minute jail sentence if you get whipped off another. The punishments also decay after one hour or after server reboots. Please remember that while these are tools for dealing with unwanted guests, some players may use them for other role playing purposes. If you find yourself being kicked/jailed off a plot and this upsets you, you simply should not return to that plot as it is not against server rules.