Lese majeste is the ancient offence of injuring the dignity of the sovereign. In western democracies, it has rightly been relegated to the dustbin of history (though it still survives in New Zealand as contempt of Parliament). Unfortunately, other countries have not. There's a case going on in Thailand at the moment which demonstrates the absurdity of such laws.
Oliver Jufer is a Swiss man living in Thailand. Last December while drunk he defaced several paintings of the Thai king with black paint. He was arrested and charged, and has now pled guilty. The minimum possible sentence he can receive for the offence is seven and a half years in jail. For defacing a painting. IMHO that's a far greater threat to the "dignity" of the sovereign than the paint ever was.
To his credit, the Thai king thinks the law is absurd and should be repealed. But in a country where the monarchy can not be publicly debated, and where advocating repeal would itself be seen as lese majeste, that seems impossible. And an absurd law with draconian penalties persists, all to protect the fiction of monarchical "dignity".