Things you need to know about Diadem (Legit and Leech alike).
*If you enter an encounter and agree upon pre-discussed loot rules (whether in DF or PF) you may liable to "Fruad" if you go against the agreed upon rules.
This is not exclusive to the Diadem. This also covers "Locking" loot, Agreements made upon someone receiving loot for a class they may not roll Need on, such as a DPS/Healer class who is substituting in an encounter as a Tank or any other pre discussed loot distribution agreements.
*If you enter an encounter and refuse to participate either by declaring verbally or non verbally, you may be held liable for "Refusal of Participation".
Both of these are offences against the games ToS and you may receive disciplinary action if a player/s chooses to report you.
How to protect yourself?
If you don't agree to the parties discussed loot distribution rules, than you should make sure to DISAGREE with them. In the event that you AGREE with them, you are bound to comply.
As for Refusal to Participate? If you are unable to participate, simply exit the duty. Life happens, sometimes this may not be an option. It is very easy to determine some one who is AFK Vs. Some one who is leeching. (Some one who is AFK - Away from keyboard; obviously will not be rolling on loot).
Simply stating things such as "Well don't blame me, blame the system" are unacceptable excuses and this behaviour must not be tolerated within the community for the betterment of everyone involved.
I have provided the information above for the community in order to better mediate itself by understanding that these actions are against the Terms of Service and those who participate in "Griefing" "Fraud" and "Harassment" will not be tolerated"
There are a number of possible future solutions which may be implemented to alleviate these problems, however I will not go into discussing those in the main post as this is mostly directed at changing the behaviour of the community by holding members accounable, rather than placing a band-aid fix on a larger issue.