Endarion wrote:D2's problem wasn't hacking in-and-of-itself, it was that people could jump in, join you, kill you, and split, in an act of unabashed griefing, and that the trade system, which should have been fun, was pointless. As long as both parties need to agree before PvP-ing, and loot drops separately so they can't jump in and steal it, then by playing with people who respect your rules (and there will be lots!) it shouldn't be a big issue.
In the end, it depends on what Runic want to achieve with their game, if they want to build a community around items and trading, or a community around modding.
I agree the lack of security to prevent dupes and cheats could ruin the game (like it kinda did with Titan Quest, but mostly because of pirated copies of the game), but if you play with your friends, it's not really a problem if you play by your rules.
It's pretty hard to enforce some kind of protection if Runic don't host the game on their servers (and I don't think they will because it costs some money, but I may be wrong...), people will always be able to generate items on their local server.
But I agree with you, it could ruin the fun, like making item runs irrelevant if you know you can dupe them. But I don't know how they could fix this except having some kind of battle.net.