As long as it's actually from a pig which has been certified as tapeworm- and disease-free, I can't see much wrong with eating any part. Pigs' trotters are supposed to be nutritious and quite tasty. And a pig's cheek was much prized as a dinner not too long ago. But additives such as chemicals, bulking, hydrogenated fats, flavour enhancers, emulsifiers etc etc are the baddies. (They used to say that only the squeal wasn't eaten!)