i like to do it. so that i can get their armor arrows and bows and misc items to sell. i end up making like 1000-2000 gold pieces by doing this in the beginning.

also why isn't there female giants?

I haven't done that, but I did run the Giant near Valhume into the bandit's. Some of those bandit's took flight.

Guards, no - pests like Thalmor and Cultists are fair game, though.

Nope, I leave the Giants alone.

Same here, except when they figure in a quest, or threaten my character directly. Herricka did Malacath's little Orc quest just last night, and had to take out several giants, not just the one who is the quest object.

The one that decided to hang around outside the door at Bettilda's Lakeview Manor had to go, too.

I have a theory that the hairy ones with the trunks are the females.

I guess I should have said it was for a bounty quest, generally speaking none of my characters mess with them, just to mess with them.

ok wth ... i was being followed by this giant and in the way he killed some whiterun guards in the area. looted everything then at one point i saw something very small fly up in the air. so i ignored it and sneaked off, and the giant went back to it's area. so then i fast travled to riverwood so that i could sell the loot. then ... lol .. everyone for no reason they all turned hostile against me? WTH? ... i checked my crimes and i didn't have anything, no bounty nothing. so then what was it?

Lollygagging and associating with giants.

For me it's more about luring annoying enemies into a group of giants. Seeing a frost troll become an unwilling participant in the Tamriel Space Agency is theraqeutic.