What are the dangers of extending my PATH?

Question

Are there any dangers of extending my PATH, say by adding /Users/me/bin?

Answer 1

It is obviously dangerous to add a directory to the PATH where other and potential malicious users can write into, where others can modify existing binaries or where you have symlinks pointing to places which can be modified by others. If instead everything is fully under your own control and only under your control then adding a directory to a PATH is less a problem. Of course, you can still screw up things by placing a binary there with the same name as a common binary but with a different behavior then an existing binary but this is shooting in your own foot.