Quick question .... I know normal, /say chat is heard only by people in your immediate vicinity, but I'm not sure who hears the general chat channel.
I know, for example, it can't be people limited to only, say, the Bazaar, or the Arcade, or the Town Square, as I see people advertising their wares and indicating that they're "by the token trader in the Bazaar," while I'm still in the Arcade myself. Likewise, when I message folks in response to their ads, they'll often tell me they're in a completely different area from me. That already breaks my expectation of what a "zone" chat really means -- as those areas are separated by loading screens, to my MMORPG-trained brain, that would make them separate zones.
Also, I know that Haven is broken up into several different numbered instances .... Haven 1, Haven 2, Haven 3 .... and similarly, people will often tell me I have to swap instances to find them.
So, does this mean that general chat is actually the GAME-wide English chat channel for absolutely anyone logged into Spiral Knights and also in Haven? To me, that should mean that the chat should be scrolling almost too fast to see. I kind of doubt it.
Then again, I can see no other means by which the chat is separated out. Anyone know for sure? I've done forum searches and checked the wiki, but it's all very vague on this specific point. None actually lay out what Spiral Knights considers to be a "zone," exactly. No reference I found indicates whether or not you're really communicating with EVERYONE logged in and in Haven.
As far as I know (which isn't much), anyone who is in the same haven as you can receive that message. Easiest way to test this is go to haven 1 and look for a familiar selling spammer, then switch to Haven 7 and see if you see that person spamming (whisper them to see if they're still online if you're bold).
The reason they tell you to swap instances though may be because they switched instances since they contacted you or etc etc.