It turns out they're relatively simple to find even -- when they've been deleted whether accidentally - or in some cases intentionally-- that too is part of the job undeleting things that people had deleted.

原来，这些图片的模式很容易找到,即使他们已经被删除,无论是因为意外还是有人故意为之-,要恢复已删除的东西,需要做这部分的工作。

哈佛公开课 - 计算机科学课程节选