I wasn't thinking of trawl, in my mind trawling is a method of fishing, such as "Trawling for shrimp". Interestingly, the second definition on that page references "Troll". Following that link, it says down the page "SEARCH, LOOK; trolling for sponsors" and "to search in or at; trolls flea markets for bargains". Perhaps both would work in the above context, however I would prefer trolling over trawling.