Let’s do the Shepard Fairey thing real quick. Oldie but a goodie.
In April, Fairey preemptively sued the AP and the AP is counter suing him, on matters of copyright and fair use. It’s over the Obama image–you might have seen it:

In this case, Shep is playing the little guy.
Unfortunately, somewhere during the fact based (not awesome, tedious) legal process, the creative little guy told a lie. Fairey submitted a less similar picture of Obama as the one he used to create his campaign image. He then deleted the actual AP image from his hard drive.
Shep wanted to make it appear that he altered the image more than he actually had. It’s a shame, really, because it shifts the focus of the argument from one about transformation and execution, to one of degree. How Much? instead of To What End?
In either case, I’m with Fairey. The idea that the AP has any rights to the Obama image Fairey created is profoundly silly.
To consider this as a case of How Much? let’s imagine ourselves as designers. It’s an awful and thankless profession, and like all real jobs, promotes horrifying neurosis and pretensions in the psyches of otherwise passive day dreamers. And yet. Consider the degree of alteration through the process of design—
Fairey has made subtle choices in creating the iconic image. He has stripped away those parts that functioned as a documentary image of a singular event, and added those parts which made it generalized, succinct, and effectively ‘viral.’ Fairey’s methodology is in line with a long tradition of reference and appropriation. It’s in a shorter tradition of computer based jpeg carousing.
He cropped. From a 2 shot to a squeeze. From a relational image to a portrait.

A freelancer named Mannie Garcia took this for the AP. No Jokin.
Fairey also transformed the million colored gradient jpeg photograph to a 5 color screen print ready vector design with considered text (font choice, size, kerning, color, position) and messaging (HOPE). If you’d like to see a tutorial approximation of the process to decide How Much? was done, it isn’t hard to find.
Fairey’s choices are simple, direct, maybe glib and de facto propagandist. At worst it’s a facile application of the posterize filter. But if you can be sued for taste, we are all basically frauds. Put that aside.
The How Much? question is far more related to an individual respect for design, and in particular, your respect for Shepard Fairy’s style of design. How Much? is the weaker of the two arguments because it asks for a valuation of aesthetic style. I believe the answer to How Much? in this case is: enough.
So let me be clear: this should not be a debate about How Much, but To What End?
Fairey’s unique and transformative contribution is his name brand. His stylistic association with the street art, grass roots, DIY community. Although Fairey’s ’street cred’ is scant and 20 years out of date, it is the most significant driving force in launching this image as a powerfully recognizable symbol.
Without the Fairey name, the AP photo bathes erroneous in the endless pool of so what? imagery, hardly worth more consideration except at the whim of a bored or desperate art director sifting, drifting, or maybe doing a think piece on relative sexiness: Clooney vs. Obama.
Fairey’s appropriation of this image transformed the Obama stare into an iconic image from a merely professional snapshot. Nevermind that Fairey’s graphic style is merely professional design. If we accept that his process fully transfered the image from one discipline to the next: from professional photography to professional design–Fairey has transformed the image and its intent and is therefore within his rights of fair use.
But Shep doesn’t always play the little guy. He’s not the ethical voice of fair use or appropriation. In this case he’s right.
In other cases, he’s ridiculious. Almost as ridiculious as his detractors (who prefer ed hardy?). Stay tuned.