From Rhizome Artbase

Deface! is disfigurement in its non-negative meaning, act of real union
between who originally made the work and its viewer. In the time of
digital reproducibility, deface! destroys artist's sacred role giving
the spectator the possibility to actively operate on the work making it
definitely of his own.
But Deface! is something more. Deface! makes the dead and static work of
art something constantly mutable, finally alive. Something that is not
there just to be admired and venerated but is indefinable, receding,
ready to be something else after every new intervention on it by
someone. And exactly with the destruction of the aura of holiness
surrounding the work and the artist and the impossibility to consider a
work concluded, finished (the work is concluded just with its
destruction), Deface! makes itself unfit for the market traffics and for
the gowned critics' soilings.
The art of Deface! is a living, open, collective art. It's the
collective destruction of art. Deface it!