ESR quote

gistfile1.txt

Constantly asking for confirmation where the answer is almost always 
“yes” conditions the user to press “yes” without thinking about it, a
habit that can have very unfortunate consequences. Programs should
request confirmation only when there is good reason to suspect that the
answer might be “no no no!” A confirmation request that is not a
surprise is a strong hint of bad design. Any confirmation prompts at all
may be a sign that what your interface really needs is an undo command.

 -- Eric S. Raymond