@nony - I had a computer crash at work and was told that if I had really important stuff on the hard drive, they could try to retrieve it using one of the services the article talks about.
The problem is that these services are very expensive as the article correctly points out. But it can be done. The reason data retrieval is possible (in most cases) is that stuff on your computer rarely gets totally deleted unless you format your drive.
Did you realize that just deleting stuff on your computer doesn’t remove it forever? It just moves it to another location from what I understand.