After last week hiring a skywriter to pen an apology to Daniel Clowes, Shia LaBeouf appeared to bait the cartoonist Tuesday on Twitter with a photo of the "Storyboard for my next short 'Daniel Boring,'" an obvious reference to both Clowes' Eightball serial "David Boring" and the actor's seemingly unending plagiarism controversy.

But while LaBeouf didn't get a rise out of Clowes, he did receive a cease-and-desist letter from the cartoonist's attorney -- which the actor promptly posted on the social media platform.

After pointing out that the storyboard drawings are copied from "David Boring," Clowes' attorney Michael J. Kump notes that, "if the foregoing isn't outrageous enough conduct by your client, Mr. LaBeouf in his tweet today plagiarized Mr. Clowes' own description of 'David Boring'" as "it's like Fassbinder meets half-baked Nabokov on Gilligan's Island." (Also worth noting: The photos fanned out beneath the drawing are of actors Patton Oswalt and Seth Rogen, who recently mocked LaBeouf's ongoing Twitter apologies.)

LaBeouf was confronted with charges of plagiarism in mid-December following the online release of his 2012 short film HowardCantour.com, an almost-direct -- and completely unauthorized -- adaptation of Clowes' 2007 comic Justin M. Damiano. LaBeouf quickly issued an apology, but even significant portions of that were found to be lifted from other sources, leading to weeks of bizarre, and frequently plagiarized, tweets from the first-time director.

In the letter to LaBeouf's lawyer Brian G. Wolf , Kump writes, "your client is clearly out of control."

"He must stop his improper and outlandish conduct directed at Mr. Clows and his works, and your clients must take all necessary and appropriate steps to redress his wrongs," Kump continues in the letter. "We have been waiting since December 27 to hear how Mr. LaBeouf intends to make right, but all that has happened is further wrongful acts, such as described above, and more foolishness such as Mr. LaBeouf's New Year's Day sky-writing frolic that exposed Mr. Clowes to further ridicule. Leave Mr. Clowes alone, and address and fix these problems immediately."