Steam has introduced a CAPTCHA test in its trading process to thwart potential malware that empties out a user's inventory.
Steam announced, and even apologized for, the new inclusion on Friday. "We know it's a bit of a hassle and we don't like making trading harder for users, but we do expect it to significantly help customers who are tricked into downloading and running malware from losing their items," Valve's John Cook said in announcing the change.
Third-party trading services approved by Steam are exempted from the CAPTCHA obligation "so they can continue to function," they added.
Steam Trading Cards, a virtual collectible that users can trade and cash in for rewards in the Steam store, launched in 2013, but the CAPTCHA applies to any form of gifting or trading. Back in November, Steam introduced a waiting period making newly purchased video games untradeable for 30 days, in order to thwart scammers who resold unusable game keys on the gray market.
For more on Steam trading, its rewards — and its risks — see this Polygon feature.