I don't know if it has been posted in this thread yet, but I seem to recall the story that the Knicks were considering cutting Lin before his contract became guaranteed. After Lin didn't look good in a game against the Celtics (Boston, the last team to hold Lin under 20 points), they wanted to see what they had in Lin, so played him more.
So, one can loosely interpret the story as Boston being responsible for unleashing Linsanity by making the Knicks doubt Lin enough to test him with more playing time.