Why does media-body class in bootstrap have width 10,000px and media class have overflow hidden and zoom 1?

Question

I have some question regarding the media classes in bootstrap.

1. Why does .media-body class in bootstrap have width 10,000px? Why did they use display: table-cell not display: block?
2. Why is overflow: hidden and zoom: 1used on .media class?
3. Why doesn't the div with .media-body actually take 10,000px width?
4. What would happen if overflow: hidden and zoom: 1 are not used in .media class?

As for my effort, I removed overflow, zoom and 10,000px width and observed no difference.

Answer 1

I have found some comments in the collection "Responsive Bootstrap":

/*
 * 1. Create new block formatting context in modern browsers
 * 2. Avoid shrink-wrap behaviour of table-cell
 * 3. Override for IE6/7
 * 4. Create new block formatting context in IE6/7
 * Alternatively, use 'overflow:hidden' if clipping is OK
*/
display: table-cell; /* 1 */
width: 10000px; /* 2 */
@include old-ie() {
    *width: auto; /* 3 */
    *zoom: 1; /* 4 */
}

UPD

*zoom is a hack for IE6 and IE7. All browsers ignore attributes that begin with an asterisk. Only IE7 and below takes them into account.