I fully agree with what this article in Slate says about the "Blurred Lines" verdict. It was wrong to find the creative team behind that song guilty of copyright infringement. Yes, I do believe that some amount of credit, and thereby money, should go to the Marvin Gaye estate, because that song so obviously bites from the specific song ("Got To Give It Up"), rather than the genre of funk more broadly. And I'm no Robin Thicke sympathizer, but the courts took it much farther than it needed to have been taken. And while, yeah sure whatever that song was focus-grouped to be a hit, it's still bad for creativity to keep artists in fear of biting too much, whether it's "paying homage" or just an accident.
I also think of the whole Sam Smith/Tom Petty thing. Obviously there are undeniable similarities between "Stay With Me" and "Won't Back Down". But to my ears they are very different songs. And I'm sure if you reached further back and deeper, you'd be able to find someone who used that very simple rhythm and very simple chord structure before Mr. Petty. Pop songwriters are working with a very limited palette and it seems perfectly reasonable to me that this was an accident. With something like the Rolling Stones/kd Lang situation in the 90's, that seems a little less likely.
Point is, maybe Sam Smith, Thicke and Pharell just fall in to the "Good" column in the Pablo Picasso model of artists as copiers and thieves, not the "Great" one. Copyrights exist for very good reason, and it certainly is a little more foggy to pick up on plagiarism in songwriting than literature. I'm no legal scholar but the "Blurred Lines" decision seems like an abuse of copyright law and I support being a little more lenient on songwriters in the wake of it. And I say this knowing you know how much I HATE burglary. Now I'm gonna go listen to "Got to Give it Up" on repeat.