Most people who played Diablo 2 in the early days have fond memories of it, but there are some out there who also have bad memories. Most of those people have played it online, which usually means one thing—they were scammed. No matter what online game you play, as long as loot is a major part of the gameplay, scamming is a constant because unscrupulous players who look for quick gains are everywhere.
Having the best Diablo 2 items in the game was and always will be a major part of the gameplay, and a lot of players didn't care how they got them. If you play in singleplayer and didn't care for obtaining them the hard way, you'd use a trainer to give your character powerful items. If you play in online multiplayer, wherein cheats are forbidden and restricted, you'd resort to scamming other players for those D2 items.
Items are scammed and accounts are stolen back in the heydays of Diablo 2, and it can still happen every now and then these days since Diablo 2 is still alive. When Diablo 3 was coming out, there was a lot of talk about hacking and scamming as well, and most drew from their experiences in Diablo 2 and World of Warcraft to protect themselves against such violations. Now that the Auction House in Diablo 3 has long been scrapped, it's not that big of a deal anymore in that game.
Most scammers back then were kids who had lots of free time to play the game and come up with shortcuts to getting powerful items in the game by taking them from other players. Blizzard would then respond much later to reports of scamming in the game with patches and bans, but not fast enough to punish everyone who violated terms and policies in the game. The scammers came up with a number of ingenious ways to get what they want.
For instance, there's what's called the DND scam, wherein you're asked for your ranking or rating in the server to join a clan or receive a free item. If you have no idea how to do that, they then tell you to type "/dnd (account name) (password)" in chat. The "/dnd" command is Do Not Disturb, which creates an away message. You will then be private messaged, and your away message containing your account information that you foolishly typed in is shown. After that, the scammer will most likely hack your account and strip your character naked.
Then there's the ever-present trade window scam, which is also present in other online action role-playing games in one form or another. You'll be shown a rare item in a trade window that they're seemingly willing to trade, but will then exit the trade window before it goes through. They'll feign an accidental mis-click and open up a trade window again. They'll then put in an item that looks like the rare item but is actually not the same one, hoping you wouldn't be diligent enough to check it. Once the trade goes through, you've just paid for a worthless item and the scammer will most likely exit the game, never to be seen again. It's basically the old switcheroo, but in computer game form.
There are plenty more of those scams, and you can find stories of people being scammed over the years in Diablo 2. It just goes to show that as good as a game is, there would always be unscrupulous people playing it, so you have to be vigilant. Players of online games are experienced enough in these things, and a lot of them gained that experience from games like Diablo 2 in the early days.