form_validation messes up the POST

[eluser]Thorpe Obazee[/eluser]
[quote author="theshiftexchange" date="1242896058"]
Sometimes you may not want to:

I sometimes dont want/need to validate a drop down list - because the 3-4 choices I give them are ALL valid - and the 'default' select on the drop-down list is what is selected 90% of the time. So why force a 'blank' validation rule to be run on the field?[/quote]

How can you be so sure that they are valid when POST can also be tampered with? I believe it's included in the "don't trust user input zone"

testing tamperingxxxxxxxxxx <-- tampered content