In a celebrity-driven incident of vandalism in our national parks, the internet exploded with reports that famed French street artist Mr. André (born André Saraiva) defaced the geology of Joshua Tree. And now Mr. André has threatened legal action against L.A.-based hiking blog Modern Hiker, who first reported the appearance of his potentially illegal art.

It all started when a reader noticed a post on Mr. André's Instagram feed showing his trademark tag on a rock in the desert, captioned "#mrA rock." The reader alerted Modern Hiker's Casey Schreiner, who inquired after the location of the rock and asked Mr. André to confirm if the piece was created with permission on private property as "something that might show his fans and followers how to be a responsible street artist." Meanwhile, some outraged Modern Hiker's readers took it upon themselves to investigate and identify the exact location of the rock, as well as documenting its appearance over the course of the last couple of weeks.

Schreiner's line of questioning and an influx of criticism from the public incited an outright feud with the artist. This has all been well-documented in a Modern Hiker blog post which Schreiner continues to update as the situation develops.

On March 3, the backlash was severe enough for Mr. André's legal team at Stefanaggi Avocats in Paris to send a cease and desist letter to Modern Hiker, demanding that Schreiner "immediately cease to disseminate the defamatory information," and furthermore "erase the infringing links and its associated files" from his website.

However, in that same letter, attorney François Stefanaggi admits to the alleged defacement, attributing "an ephemeral creation" in Joshua Tree to Mr. André, who reportedly used "water-based paint" to place "his artistic signature" on a rock. Stefanaggi also claims that Mr. André subsequently "erased the inscription and made all mark of this short-lived performance disappear."

Mr. André's lawyer threatens to "pursue all available legal remedies" against Modern Hiker, including seeking damages for "publishing detrimental messages...with the intention to discredit [Mr. André's] professional works and harm his artistic reputation."

In a new post, Modern Hiker reprinted his own lawyer's response, and declaring that the site "has no intention" of removing its original story.

Responding to Mr. André's litigation threats, Schreiner's legal representatives at Levine Sullivan Koch & Schulz, LLP in Washington, DC reminded Stefanaggi that "truthful statements are not actionably defamatory," and that Mr. André himself bears the burden of proving the article in question was "false in some substantial way." Furthermore, it says, "it is irrelevant...whether [Mr. André] voluntarily removed the inscription 'a few days later.'"

Subsequent photos posted on social media and shared with Modern Hiker by its followers appear to show that Mr. André's tag, in fact, no longer appears on the boulder, but whether it is in fact the same exact boulder in the same exact location are still unverified. At press time, Joshua Tree National Park has not claimed responsibility for any removal or coverage of the defacing tag, and declined to comment while the situation is still under investigation.

Why would Schreiner publish the actual letters online, when it could possibly inflame the situation further? "My primary concern is to make sure this story remains in the public light," he said, "and if [Mr. André] is guilty, [that] he's held accountable to the fullest extent of the law."

Graffiti in our nation's parklands is unfortunately common, particularly in Southern California. Two years ago, Joshua Tree National Park was forced to temporarily close two of its historic sites, Barker Dam and Rattlesnake Canyon, from further damage. In the case of Rattlesnake Canyon, park staff blamed social media for the rampant spread of what began as just a few markings. When vandals bragged about their artwork online, others would follow suit, coming to the site armed with spray paint.

Although the vandalism at those sites was much more severe than this one tag on this one rock, this new incident is far more public because of the notoriety of the alleged vandal. As a high-profile street artist, Mr. André can count many admirers -- and potential copycats -- among his social media followers.

Schreiner fears that people who are uneducated about the outdoors or how to behave in wilderness areas may not understand that any defacement (even one that is removed) is highly illegal and punishable by fine and imprisonment. In short, he says, "Please don't do this in the outdoors."