1. No pressure is brought (Obama's not even up for re-election, but I wouldn't feel differently if he were) 2. Usually the only people who know about a petition

1. No pressure is brought (Obama's not even up for re-election, but I wouldn't feel differently if he were) 2. Usually the only people who know about a petition are already aware of the issue (case in point, unlocking cellphones petition on HN)