For the first time since box office reporting became a Sunday-morning ritual in the early 1990s, Hollywood’s majors — and a good many smaller distribs — banded together to withhold touting domestic box office returns, out of respect for the victims of the shooting in Aurora, Colo., at the midnight screening of “The Dark Knight Rises.”While there was never a question that “TDKR” would rank as one of the biggest Stateside openings ever, the results ($160.9 million; good for third-best) weren’t reported until after the weekend, and even then WB decided to release only the numbers, without the chest-thumping usually associated with such achievements. The other studios followed suit, though no other film opened wide alongside “TDKR.” That said, it’s clear that some pics were affected by the tragic event: Fox’s “Ice Age: Continental Drift” fell 56% in its second sesh, earning $20.4 million, though the family film figures to have had little direct competition from the fanboy pic. The toon dropped considerably more than its predecessors during their comparable frame. Universal’s “Ted” fell 55% for a weekend gross of $10 million, in part due to competition from the Batman sequel. “Ted” dropped 41% in its second frame. Theater owners reacted quickly in the wake of the Colorado shooting, boosting security and banning costumes in plexes nationwide.