Authority and Multiplayer on Input Movement

Hello! Should I care about making “Add Input Movement” to be calculated on the server side only (authority true)?

Most of examples I see, people don’t care about making the movement authority only. Isn’t it possible to hijack the memory where the client is running and make the character hover or run faster or teleport?

I see a lot of texts and tutorials talking about things like Damage, Health and so on should be server side only, but all examples I see of multiplayer people just don’t care about the movement.

Am I being paranoid?

Hello,

I ve made some explanation about this (I think). My purpose is the player pressed key to forward, turn… but it is server which will apply movement, and send new location to all client.

http://thyshimrod.blogspot.fr/

I hope it will help you

ps: Otherwise don’t hesitate to write specific question