Naughty? What, like children?
deface
/dɪˈfeɪs/
verb
past tense: defaced; past participle: defaced
spoil the surface or appearance of (something), for example by drawing or writing on it.
"he defaced library books"
synonyms: vandalize, disfigure, mar, spoil, ruin, deform, sully, tarnish, damage; More
injure, uglify, blight, blemish, impair;
informaltag, trash
"a graffiti artist who defaced buildings and motorway bridges"
er Vandalise?