Vandals is it? You know what they used to do when they caught schoolkids painting grafitti on the school. Of course this isn't just a brick wall on a school, so they will have to get some pros to get the paint off without damaging the art.
Elamite-speakers are mentioned in the New Testament (Acts 2) as one of the groups which heard the apostles preaching in their own language on Pentecost in Jerusalem. Elamite was also one of the three languages on King Darius' inscription at Behistun in which he describes how he became king of the Persian Empire.