what can we do about it [legally]?
Depends what country you are in.....
In America: you call the cops document it and file a civil or criminal suit depending on the access of the property.
In Russia:you get your pals to shoot them:)
In China:you ask for money from the proceed.
In India: you get a priest and pray together and ask for money.
In POLAND:mixuture of all the above.