There is a mechanic on these items to limit how often and how much they can drop each day. A normal game session for a day should not be impacted.
by panderus
Unfortunately it seems that the daily limit does impact a normal game session, or at least a LEGIT farming (human control over toon, farming in normal game areas, like fiery pit). I run out of daily limit after less than 1 hour farm. The uproar on forums about dragon hoard enchantments means that it affects more people - unless there are botters only complaining, which I dont really believe. If you found this to be only solution to fight botters - at least tweak it not to affect normal players.