I was setting up a Wordpress site for someone once (I'm not really a web developer). I downloaded an image gallery plugin and installed it locally. Wouldn't work. I went to the instructions and found that it required wp-content/upload to be set to 777. I abandoned the plugin soon after. However, if I hadn't been running Linux for a year before that, I'd probably have just done it.

The difficulty with the democratisation of software and web development is that inevitably, people will make mistakes like this. The sad part is there's probably millions of articles explaining why this is a bad idea, but the people most at risk will never see them.