Is Apple’s legal action against HTC a little like Microsoft against SCO?

I wonder what sparked Apple to start pursuing legal action against HTC for infringing on their iPhone technology related patents? And given that HTC is just one of many companies that are now producing Google Android powered phoned, why HTC in particular? Why not Google themselves, since HTC are using Android on the phones that I’m guessing this is what Apple are concerned with? Why not Motorola, Samsung, HP, Sony/Ericsson or any of the other companies?

Doesn’t this sound a little like Microsoft going after SCO for the Linux debacle in the past? Trying to pick off the small guy in the pack since it’s more likely they’ll win against the small guy but have less chance with someone like Google?