Sentence:  The solitary, lumbering trolls of Scandinavian mythology would sometimes be turned to stone by <WSD>exposure</WSD> to sunlight. Barack Obama is hoping that several measures announced on June 4th will have a similarly paralysing effect on their modern incarnation, the patent troll. 
Meaning of the word marked with <WSD> tags:  (condition) The condition of being exposed, uncovered, or unprotected.