I'm impatient, so I'll admit, I tend to look stuff from stories up as soon as the story details are available. The first thing I did on the release date for STID was look it up on Wikipedia to see who Harrison really was.
Interesting. I guess I'm one of those people that try to avoid most spoilers beforehand. But before I saw STID, I had been spoiled on every major plot point (and a bunch of minor ones). I had deliberately avoided articles and stuff online that were stated to be related to STID, but the spoilers all came from either here or io9 comment sections in articles that had nothing specifically to do with STID!

(To be fair, I did see the movie much later than most due to some personal issues, but I still deliberately tried to avoid spoilers during that time.)
Yeah I think if the title says SPOILERS and I go in the thread and I am spoiled (even a major spoiler) then it is entirely my fault as the reader.
Yeah, this. For review threads that have "Spoilers" right in the title... I don't read the thread until I've finished the book. It's not that hard. If you go in there before reading the book, well, you were warned up front, and if you see something you wish you didn't, it's on you.
The worst part is, though, when people put the spoiler itself in the title of the thread. That takes away your ability to decide whether to subject yourself to the spoiler or not. And then tagging a spoilery thread title with "(Spoilers!)" just adds insult to injury!