Yeah so... A rather big lie by Todd Howard. He said something like Giants are normally peaceful unless you attack them? LIES!

I went close to a giant and it waved at me, i thought it was saying hello so i walked up to it. Next thing i know two shots later im flying into the air. Thanks Todd. That was really good by the way. I was just glad i saved.

I'm pretty sure some armed gnat walking right up to your shins constitutes an attack, rather than waiting for you to actually hit it.

I heard waving weapons in front of their face means hello to giants.

I didnt have my weapons out.

they agro u when u get close, like some bandits say 'thats far enough' and wont agro u either. so i guess a giant waving means gtfo lol

Well I tried following some giants, and kept getting closer and closer.. after a little while I was walking next to one, and he AND the others didn't mind.

There is a tooltip that says Giants are cool with people so long as they don't get too close to them or their Mammoths. Also, you can find a note pinned to a signpost near a Giant camp that says 'Don't go near the Giant. They will eff you up.'

The walking giants don't mind too much but when you bother them during their downtime they start playing golf.

hmm so maybe its only the camp giants beeing agro then ;p

That's been my experience. I walked up to one at camp, he turned me into paste.

I walked up to one wandering around the wilds alone, he completely ignored me.

I led some of the soldiers when I was free roaming into the Giant terroritory. Boy, am I flamboyant.

I came upon a giant in a camp and it made threatening moves at me so I just walked on by, no problem. I haven't seen many yet though.

The AI and the enemies are intelligent in this. Case in point: Just wandering around at night out in the open. I hear this elfmaid crying and she asks for help. I get up close to chat and she attacks me. Her status bar says "Vampire Thrall." Then her stupid boyfriend comes out from behind a tree and chides me for falling for it. I take her down easy but dude is also a conjurer/vampire and he summons two poison spiders. Whoops! I forgot my magic sword lost its charges and girl gets right back up 2 seconds later with immediate half-health. No time to switch to silver sword.

What I really hate, aside from giants playing with you, is when an enemy capitulates and then when you decide to sheath, he jumps right back at you! I'm no longer falling for any of these shenanigans again. No more Mister Nice Guy.

I think the lie was you could talk to them. I saw a talk option on the demo Todd played.

Not sure it also may be down to how aggro'd they already are. I approached one after we fought a Dragon together and he pulled out his weapon. I put mine away and backed off and he put his away. I tried to go near him again sans weapon but he pulled his, so I backed off and he went soft again. I haven't really tried any others. I followed the farmer with the sacrificial cow to give the giants but I couldn't see what happened to him. They saw me, but I was still far enough away it didn't seem to matter. I've been operating under the theory that as long as you stay far enough away they won't go after you.

That makes sense doesn't it. You're encroaching on their territory, and so they feel the need to protect it. Just like in real life, with real animals defending their territories from humans and other animals.

It's locat ion. They have home bases. If you just bust in on their house and expect them to break out the snacks for you then they offer you wood. If you see them walking around herding mammoths then they have more to worry about.

it's more complex then a non agressive flag but something related to situations. You'll notice that when you walk in their home they shake their club a while before they become aggressive. it isn't the hokey pokey.

I walked right past one on the main road near Whiterun and there was no hostility at all. It passed by me without a second glance.
I did however get one shotted by one that decided to attack Dawnstar the exact same moment as a Dragon attacked the city. I found it hilarious

They attacked me and my follower as well. I was just passing through when I noticed a giant standing next to the road. When I continued my journey out of nowhere he became aggressive and killed my companion. I'd rather have the loading screens say that the giant race is aggressive towards anyone that travels nearby, than that they aren't aggressive at all.

I think there are more flaws in the game like this one though. It's only a minor part of the game, obviously, but it still causes some confusion to me, and probably others, when things like this happen.

I ran near some group with mammoths as well. I was hunting deer for leather when I came across them. A giant waved its weapon over its head as we got close so I backed off and the giant went back to plodding around the herd.

Damn, it usually only takes them one shot to kill me.

Giants are non-hostile. Just don't go near their mammoths. I went up to a giant and he was fine, but his mammoth got funny and so did he too. They are killable though, just a little bit of a challenge. I killed one and a mammoth at level five at the cost of ...LYDIA!!!! WHY!!!!???

They don't like people going near their camps. When they're out on the move, they're fine.

I totally agree. I do absolutely nothing to the giants and from a far distance they always just come running towards me and start attacking me. The mammoths too. I was in the hot-springs area on the other side of that mountain near Whiterun and the mammoths just attacked me along with a dragon. It really keeps you on your feet, you have to be secret I guess. The same goes for the fields of Whiterun.

My rule of thumb:

Dont go to the giants camps or mammoths, they, so far, have always been non hostile when they wander around in the wild with no mammoths.