Just saw this explanation on VeryCD forum, seem quite plausible:
其实很简单,只要用可以防吸血驴的电驴mod就可以了,把防吸血驴的设置打开,就几乎没有文件损坏了,关掉后马上出现大量文件损坏
为什么有人说用xtreme版就没有文件损坏了,就是因为cn版,xtreme版以及其他很多版本都有防吸血功能,默认都是打开的
胡乱猜测一下,为什么开了防吸血功能就没有文件损坏了呢,我认为有2个可能,
一是有恶意的吸血驴mod伪装自己有完整文件,积极上传以骗取优先下载的机会,但是上传的数据都是假的
二是可能有反盗版的机构乱传假数据,打击电驴的使用
If that is true, that can also explain why the gain due to compression is so high lately. As normally most download are either video or zipped file which does not really compress again, if the data are instead just random data then the potential to compress it will be greater.