In game, I see a lot of AFK (away from keyboard) players. Does being AFK allow you to get items from the item drop system?
Regarding your question, valve adressed this issue of idling a while ago and came up with new restriction that affect the way items are dropped in this game. check it
A short extract from the webpage:
What is the definition of “actively playing” Team Fortress 2?
I recommend you read the whole blog post, but all in all from what i understand you can still idle but unless you check your new item drops you can't get any other item drops.
Yes. Well, sorta. All that's required really is to be in game and connected to a VAC server and that they acknowledge drops as they happen.
You can very simply click on "Steam Workshop", pick "Start test map", join a team and leave in the background. Check regularly for drops so you can get more. You can use an auto-updating browser tab such as tf2b to know when you need to act.
Yes they can get item drops. However, there is a limit to the number of items that you can get in a given period, so idling for items has limited benefit. Valve tweaks the system every so often to try and discourage idling for items.
From the TF2 Wiki:
Furthermore, I believe Valve is capable of tracking people who have accounts solely for idling, and mark them with lower drop rates. That much is speculation, based on observation of a relatively small sample size, although there is precedent.
Server operators can install plugins that kick idle players off after a period of time, and there are even servers that exist for the sole purpose of idling and trading items, so you should shop around in the server browser until you find one that is routinely policed for AFK players, if that is of concern to you.