Nothing wrong with trying to destroy other team by stealing their members?!

Oooooooooooooookay.

"destroy", "stealing", what world are you living in? You don't steal people, they leave or stay of their own free will. They're not trying to destroy you, they're trying to succeed for themselves, and making an offer to a talented hacker at any time is perfectly legit. To think otherwise is silly, the other team doesn't owe anyone anything. If I offer a hacker from another company 20% more $$ to come work for me and he takes it, that's called business, not "stealing and destroying". Besides, you can always match the offer.

It's probably fair game to make an offer to anybody you like, but to expect friendly responses from their colleagues would be asking too much. Think about other men hitting on your girl-friend. It is certainly legal to do so, but you probably wouldn't welcome it too much yourself.

No one likes being out competed, that's a given, but no one should cry about it publicly like they were wronged, especially if they actually won by not losing their partner. More to the point, never act like you own another human being and are somehow wronged by someone making them an offer, the same would apply to a girlfriend.

Fair game is exactly the right phrase, in business offering anyone more money or a better opportunity is always fair game, hell, that is the damn game. Want to keep your talent, then make sure you give them a fair deal and don't begrudge them a better deal than you can offer should it come along.

It's unbelievably arrogant to continually refer to someone as my hacker in such a possessive manner, you may as well be saying my ignorant slave. That hacker is likely much smarter than you are, give him some respect and stop talking about him like property.

No one is ever stolen in an adult relationship, only children think that, adults leave, there's a world of difference.