It seems crazy you could get banned from a traded steam gift. How would anybody really know when its legit to trade? I can understand if you obtained a key from an incorrect region and used vpn to activate. In this case you are obviously working around the system and therefore accepting the risk. I just don't see how steam trading could be fairly policed
Because it is crazy. And unfortunately Steam's TOS gives Valve broad powers in determining who is violating their rules. I have read cases where people have been banned and asked for an explanation and received nearly none.
Not all regional keys require VPN (very few do, relatively) but their origin is obvious. Publishers keep track of which keys get issued where if they care to, we know this because a game like X-Com seemed region free, only for people to find out later it was region-locked. And Valve obviously knows the source of every Steam gift. That being said, they really don't do much to prohibit regional trading between users.
In my own opinion, I think a few of these per year are normally okay, unless Valve is doing a ban in waves for regional pricing offenders (which they do sometimes, either to make an example or to people who severely abuse the system, who knows) and some unlucky people get caught up in these.
But as someone else said, our regional sellers are honest, and people who buy from them know that they are taking on a certain level of risk when they do (however minimal, it is there).
From my experience, the only way to get banned by Steam is to buy games with Stolen Credit Card or do multiple chargebacks. That is perma- ban. People who bypass regional pricing by using VPN (I don't even know whether this is possible or not) will get their accounts restricted (means no more buying, trading or activating keys but games already in library will be fine). Also if somebody took a "giftable" (means not yet tradable - in the 30 days not trustable account purchase) game from another guy and it was purchased with a stolen CC or got a chargeback, the victim will get his account restricted untill he/she contacts support and they will fix it ASAP
XCOM incident was a rare case. It was (RU) tagged since day one for the pre-order but it could be activated and played worldwide, then suddenly Steam locked it. So as long as the game is not tagged, it is 100% safe... hmm, maybe 99.999% lol . Borderlands 2 Season Pass was NOT tagged in Russia but because there was a price error (was $4 lol) Steam did the weirdest thing ever; tagging and locking every Season Pass from all regions (not just Russia!) as RU/CIS and locked it for people who still had it in their inventories. Those who added it to libraries got away with it but still turned to Borderlands 2 Season Pass RU CIS in Licenses and subscriptions list. I bought it for $10 from a guy and added it directly to my library and it still works just fine
I am sure that Valve is breaking dozens of laws, so they would not care for banning people for anything other than the most severe cases