 This is a reader video found on Macrumors forums illustrating something weird. Wired.com readers are also reporting the problem: Out of more than 40 respondents, about 35 are reporting a similar pattern of problems: If you hold the iPhone 4 in your left hand, or touch the lower-left corner of the outside steel band, the signal indicator starts losing bars within a few seconds. Hold it carefully by the glass, avoiding the new steel antenna band that runs around the edges. Even Walt Mossberg, in his review of the iPhone 4, had an eerily similar-sounding experience: 
 
 [O]n at least six occasions during my tests, the new iPhone was either reporting “no service” or searching for a network while the old one, held in my other hand, was showing at least a couple of bars. In the current iPhone firmware, this is not yet reflected in the signal display, which still indicates actual strength. But how does that explain the images below, in Update 4? Many respondents indicated that this led to dropped calls, and one, “Edward,” did download speed tests that showed a dramatic drop in throughput when holding the iPhone 4 in his hand, from 2Mbps to a measly 12Kbps. Chris also says he went do dial a number when he lost signal with his hand on it, and could not get a call out. Update 7: Reader Sam says it only happens to him when touches the left side, connecting both antennas. When the phone hits 1 bar, he can still make a call, but not when it's "searching for signal." The problem is also repeatable, making it look like a lot more than simple coincidence. Two people have reported that keeping the iPhone 4 in its protective “bumper” case eliminates the problem, probably because it is an electrical insulator and prevents the antenna band from contacting the conductive surface of the skin. Two respondents have said that they’ve observed the same diminishing-signal problem with previous models of the iPhone. Update 25: Reader Patrick tests his with a case and without a case, showing that it is the case that's protecting it. Touch means that a larger portion of the antenna energy turns into heat and lost. Update 43: Reader Javier says he got a Griffin Reveal for iPhone 4 case, and although it's a nice case and all, it does not help the reception issue at all. You will almost certainly see your signal disappear, or drop by three or four bars.
– When you hold the iPhone in your hands and touch the outside antenna band in two spots, it can drop reception (or at least lose bars). Put the phone down and your bars return. Gizmodo has the details of this odd glitch along with reader-submitted videos of the problem. (A rubber case seems to solve it.) Read the full article. More info at Wired.