Wait, really? I didn't know that :P
Yeah, I agree that a DM harassing a group of players for playing the game is a bad thing. The most egregious advice that I'm giving is for when a group like the PCs has earned the wrath of an organized and intelligent organization of NPCs and they have not prevented that group from gathering information about them and bringing their power to bear. To some extent, in that situation, the PCs have lost and they just don't necessarily understand the mechanics of the last ten moves in that chess game. You can play it out for them, but the real way for a group to avoid these consequences is to not get into that situation in the first place.