Can't enter giveaway on free weekend

Currently Brink is in my games library (and everyone elses) for the next 21 hours, until then I and everyone who hasn't had their account synced recently can not enter a Brink giveaway (other than the Complete Pack)

Surely there should be something to know when there is a free weekend happening and either not allow those games to be gifted, or maybe have a popup warning to make sure you want to enter the giveaway and allow everyone to enter.