????視頻監控是門大生意，而且還會變得更大。執法部門使用閉路電視（CCTV）攝像機確認了上周波士頓爆炸案的犯罪嫌疑人之后，國會議員和監控措施支持者再次呼吁在全美各地增加攝像頭的數量。

????“我們需要更多的攝像頭，現在就需要，”《石板》雜志（Slate）一篇報道的標題寫到。

????紐約州共和黨眾議員彼得?金對此深以為然。他在爆炸案發生后接受MSNBC廣播公司記者安德里亞?米切爾采訪時強烈呼吁加大視頻監控，唯如此，我們才能“比恐怖分子先行一步。”

????他說：“是的，我非常贊同增加攝像機的提議。”身為美國眾議院國土安全和情報委員會委員的彼得?金還呼吁加強對美國穆斯林的監控力度。“這些裝備是了不起的執法手段。我再次強調，視頻監控可以讓我們掌握先機，比恐怖分子先行一步。這些家伙時時刻刻都在尋思著要我們的命。”

????幾乎可以肯定的是，紐約市的執法官員非常愿意幫這個忙。紐約市警察局（NYPD）局長雷?凱利希望“顯著增加”曼哈頓的監視設備數量。曼哈頓現在已經是美國監控體系最完善的地區之一。

????贊成加強監控的觀點直截了當，顯而易見。波士頓等地發生的恐怖事件警示我們，我們其實很容易受到傷害，非常脆弱。這種觀點認為，遏制爆炸案這類恐怖事件的最佳方式就是在公共場所實施24小時監控。看到有人被炸彈彈片致殘那一幕時，所謂的隱私問題聽起來是那么地冰冷而抽象。

????當然，再多的安保措施也無法徹底消除風險，因此我們很難知道合理的界限究竟在哪里。10,000個攝像頭的安保效果真的就比5,000個攝像頭好兩倍嗎？現在，悲劇的余波還未完全散盡，我們很難就安保投資額度究竟應該有多大這個問題展開一場嚴肅的討論。但是，一旦防范目標變成盡可能地把風險降低到趨于零時，相關開支就有可能漸漸擴大到無窮大。

比不良資產救助計劃和新政的規模還要大

????美國對于這種困境并不陌生。為了響應911事件后美國人對安全的關切，聯邦政府慷慨地打開了錢袋，一個龐大的國內安全體系由此產生。根據瑪蒂亞?克雷默和克里斯?海爾曼發布在Tomdispatch網的報道，911事件后，聯邦政府用于國土安全的開支超過了7,900億美元，規模比不良資產救助計劃（TARP）和剔除通脹因素后的羅斯福新政（New Deal）還要龐大。

????我們無法獲悉美國國內監控開支的確切數據。市政當局不是特別樂意公開已經安裝的攝像頭數量。許多情況下，國土安全補助計劃并不要求各大城市提供它們各自運用聯邦資金的明細開支。

????盡管如此，美國的投資已經帶動全球視頻監控行業強勢增長。根據市場研究機構Electronics.ca Publications 于2011年發布的一份報告，到2015年，視頻監控市場的規模預計將從2008年的115億美元增長至375億美元。

????Video surveillance is big business. Expect it to get bigger. After law enforcement used closed-circuit television (CCTV) cameras to help identify last week's Boston bombing suspects, lawmakers and surveillance advocates renewed calls for increased numbers of cameras nationwide.

????"We need more cameras, and we need them now," ran a Slate headline.

????Rep. Peter King (R-NY) agrees. In an interview the day after the bombings with MSNBC's Andrea Mitchell, he called for more video surveillance so that we can "stay ahead of the terrorists."

????"So yes, I do favor more cameras," said King, who sits on the U.S. House Homeland Security and Intelligence committees and has also called for increased monitoring of Muslim Americans."They're a great law enforcement method and device. And again, it keeps us ahead of the terrorists, who are constantly trying to kill us."

????Law enforcement officials in New York are almost certain to oblige. NYPD Commissioner Ray Kelly wants to "increase significantly" the amount of surveillance equipment in Manhattan, which already has one of the country's most robust systems.

????The argument for greater surveillance is straightforward. Horrible events in places like Boston remind us that we're vulnerable. The best way to limit events like last week's bombings, the argument goes, is to accept 24-hour surveillance in public spaces. And when you see someone maimed by bomb shrapnel, privacy concerns sound coldly abstract.

????No amount of security can completely eliminate risk, so it's difficult to know where to draw the line. Are 10,000 cameras really twice as good as 5,000? In tragedy's aftermath, it can be tough to have a serious conversation about how much to invest. But when the goal is to push risk as close to zero as possible, spending can asymptotically stretch into infinity.

Bigger than TARP and the New Deal

????The U.S. is no stranger to this dilemma. In response to security concerns after 9/11, Americans witnessed the growth of a massive domestic security apparatus, fueled by federal largesse. According to Tomdispatch's Mattea Kramer and Chris Heilman, post-9/11 federal spending on homeland security exceeds $790 billion. That's larger than TARP and, when adjusted for inflation, the New Deal.

????Exactly how much the U.S. has spent on domestic surveillance is murky. Municipalities aren't particularly keen on sharing how many cameras they've installed. And homeland security grant funding, in many cases, does not require a line-item accounting of how cities have used federal funds.

????Nevertheless, U.S. investment has helped fuel the growth of a global video surveillance industry. According to a 2011 report by Electronics.ca Publications, a market research firm, the video surveillance market was slated to grow from $11.5 billion in 2008 to $37.5 billion in 2015.