"exercised [...] shares"? That's not a meaningful sentence, so it's not clear what situation you're trying to describe. In any case, either your partners can

"exercised [...] shares"? That's not a meaningful sentence, so it's not clear what situation you're trying to describe. In any case, either your partners can (in this example) dilute you or they can't. Neither of these is a fundamentally dishonest situation, you just have to make sure that everybody and their lawyer is on the same page as to which it is (and write your contracts accordingly). Same with copyrights. People will be understandably aggrieved if they create works believing that the law will protect them and then it doesn't. But if we change the law so that new works created in future are not eligible for copyright protection, there's no such problem (because everybody should know what to expect).