they could submit their e-mail addresses to reveal a pixel of a concealed Joker image; about 97,000 e-mail addresses and 20 hours were required to reveal the image in full, which was well-received. At the San Diego Comic-Con, 42 Entertainment modified 11,000 one-dollar bills with the Joker's image and the phrase "Why So Serious?" that led finders to a location. 42 Entertainment's initial plan to throw the bills from a balcony was canceled due to safety concerns, so the bills were covertly distributed to attendees. Although the event was expected to attract a few thousand people, 650,000 arrived and participated in activities that included calling a number taken from a plane flying overhead and wearing Joker makeup to commit disruptive acts with actors. Globally, fans photographed letters on signs to form a ransom note. A U.S.-centric effort involved people recovering cellphones made by Nokia—a brand partner to the film—from a cake, which led to an early screening of the film's bank-heist prologue before its public release in December. Ledger's appearance in the prologue was well-received and positively changed the discourse around his casting. Following Ledger's death, the campaign continued unchanged with a focus on Dent's election, which was influenced by the ongoing 2008 United States presidential election. Warner Bros. was concerned public knowledge of Dent's character was poor; the campaign included signs, stickers, and "Dentmobiles" visiting U.S. cities to raise his profile. The campaign concluded in July with displays of the Bat-Signal in Chicago and New York City that were eventually defaced by the Joker. Industry professionals considered the campaign innovative and successful. Warner Bros. dedicated six months to anti-piracy methods; the film industry lost an estimated $6.1billion to piracy in 2005. Delivery methods of film reels were randomized and copies had a chain of custody to track who had access. Some theater staff were given night-vision goggles to identify people recording The Dark Knight, and one person was caught in Kansas City. Warner Bros. considered its strategy a success, delaying the appearance of the first "poorly-lit" camcorder version until 38–48 hours after its earliest global release in Australia. Context Compared to 2007's $9.7billion box-office take, in 2008, lower revenues were expected due to the large number of comedies competing against each other and the release of films with dark tones, such as The Dark Knight, during a period of rising living costs and election fatigue in the U.S. Fewer