snowball rumors 以讹传讹

“以讹传讹”，汉语成语，“讹”表示“false information”，以讹传讹指把本来就不正确或不符合实际情况的话又不正确地传出去，越传越错（A false report, once released, will remain so in its circulation），可以翻译为be wrongly informed; pass on wrong reports; snowball rumors。

让我这个目击者来告诉他们所发生的事情，也免得以讹传讹。

Let me, as a witness, tell them what happened so that they will not be wrongly informed.

以讹传讹造成的悲剧真是太多了。

There are really a great many tragedies caused by spreading false news.