Let's go with the Coldplay-Satriani case. Let me clear right off the bat that I like the work of both parties, and hold respect for each. I do take a side in this case though, and that case is Coldplay's.

First off, the album was released in June. The accusation was made in November. It was featured all over the internet, in a few ads, reached #1 on various charts both in it's album and as a single beforehand, why did it take Satch so long, and suspiciously close to the Grammies, after their nomination? Personally I think this is related to the fact he's been nominated 15 times and never won, but I digress. Let's move onto factual things, shall we?

Despite being similar, the chords are actually different. Coldplay's Viva La Vida is Db, Eb, A, Fm. Satriani's If I Could Fly is Em7, AMaj, Dmaj7, Bm. Key-wise, VLV is in F Minor, IICF is in B Minor. If we go with chord positions, VLV is 6-7-3-1, IICF is 4-7-3-1. Now, Satch is an incredibly knowledgeable guy on theory and stuff like this. I have no doubt he could've realized these differences.

And moving a bit farther in, a Spanish(?) guy can sue Satch if Satch can sue Coldplay. The Enanitos Verdes song Frances Limon has the same riff nearly identically, and was apparently released beforehand.

So yes, feel free to leave your thoughts, but do give them a logical backing please.