Vladimir Umanets painted a message onto a Mark Rothko painting in the Tate Modern, and has just been arrested - bbc.co.uk

He claims it's not vandalism and his fellow 'Yellowists' say that he simply 'signed' the painting to "show that this painting is a potential piece of Yellowism." - thisisyellowism.com

There's an established tradition of artists (& non-artists) making changes to existing artworks. Can this 'vandalism' ever be acceptable?

So he's been charged today and pleaded not guilty. bbc.co.uk
Looking at the altered image it does look like vandalism, but it will be cleaned off & restored. The digital versions of the altered image will, however continue to exist and arguably, they are the record of the 'art event'.
I think it is interesting and just maybe there is a case for allowing an art work to be altered in this way. By characterising it as 'vandalism' we are already seeing it as damage, rather than a change. I might feel differently if it was a piece I really loved! How should we decide where to draw the line?

I agree that it's perfectly possible to create a new art work (or art event) by modifying, temporarily or permanently, an existing work. I remember watching Michael Landy doing this by shredding all of his possessions (including works by Tracey Emin and Damien Hurst) back in 2001: news.bbc.co.uk

The difference here though is that the art work didn't belong to the person who painted a message on it, and was instead hanging in a public gallery (I'm not sure who owns it precisely).

Does the quality of the original art work or the alteration has a bearing on the acceptability of this kind of behaviour?

Does being in a gallery lend a certain sanctity to original works, in a way that being on the street (like statues) doesn't?

I was wondring about that aspect - even in the yellowist manifesto they state a yellowist work can never exist in an art gallery so they've created a paradox.

It seems like a feeble imitation of Duchamp to me. They had a context and a reason back then, which doesn't seem applicable now. This so called "yellowism" adds nothing except notoriety for its own sake. Which is a bit like being famous for being famous. Except they are nearly forgotten already.

Their manifesto does seem to be a an exercise in saying nothing: they claim that anything can be an example of yellowism if placed in a yellowistic context. Which I suppose is a comment upon art but not a particularly new one.

However the question here is whether vandalising public artworks can ever be acceptable. Are there any examples of galleries accepting a defacement rather than restoring?

That once happend here in Brazil, or something similar. But, it is important to say, in our biggest and most important art event, Bienal Internacional de São Paulo (Sao Paulo Bienal), by a group of graffiti art called PixaçãoSP. Their first "participation" (without being invited to) was in 2008, by intervening in an empty floor of the Bienal building. You can find some photos here: flickr.com

As I can remember, the Bienal organization did not erased their intervention. But in the next Bienal, in 2010, they did it again. At this time, not on the walls, but on an instalation by Nuno Ramos. And this one was erased by the Bienal organizers. Another picture here: goo.gl

This different reactions is, for me, closely related with the context. In the first case, was on an empty floor and only on the walls. This floor was empty because of a curatorial decidion for its problems with funding, and was kind of a political act leaving it empty. And then came PixaçãoSP and filled it with some graffiti.

On the other hand, in 2010, as they intervened on an installation, and it was also a kind of "ressurection" of the Bienal foundation (with the change of the board of Directors), they were not actually welcome to do it again, and the political contexto did not allow then to stay "exposed".

Again (as always in art as I see), the context is absolutely important to the acceptance or rejection of this kind of work.

It must be a balance between the expectations of the creator *and* the owner of the work. You could think of the kinds of works which get shared and re-worked regularly—such as those licensed through the Creative Commons.

There are things meant for participation, and others which can be legitimately re-worked. However, the artist and the owner of the artwork (or curator) would be the ones to decide whether this is acceptable, and what kind of reworking would be appropriate.

I'm sure there are legitimate reworkings of art, and engagement based on altering an instance, but this seems pretty straightforwardly vandalism, doesn't it?

I agree with you, Zach Beauvais. And even if a work is not meant for participation, there are artists whose interventions in other's works much more respectfully than what these group did. Another brazilian artist, Eduardo Srur, does it very cleverly, like in this image, exposing the out careless statues in São Paulo, almost claming for "salvation" from a disaster: goo.gl

The title of this thread refers to "public" art works - that Rothko piece is not a public art work, but owned by a private gallery. So in that case, yes it appears the argument is moot - tho shalt not walk onto private property and defile.

In terms of actual public art - such as the photo above - I think all is fair game. Often these statues/works of art are decided without consultation to the public, but uses the public's money. Any artist placing a piece out somewhere in the city cannot expect it to be immune to its environment. In other words, it's all fair game once it's put out there. The public has the right to react however they choose to it - seeing as it belongs to them, anyways.