Hey I think what you're looking for is in the relationships menu. When you select a name you can push G(for PC) and see the users steam profile and then add them as a friend. This also works for people who have invaded you, direct and indirect retaliation targets, the intruder list, and even the random infiltration target list.

Hey I think what you're looking for is in the relationships menu. When you select a name you can push G(for PC) and see the users steam profile and then add them as a friend. This also works for people who have invaded you, direct and indirect retaliation targets, the intruder list, and even the random infiltration target list.

Yeah there's no function like what I think you're talking about. You can't add Steam friends, it's completely random as far as I've seen. You can indeed friend the random people you find though. Not much of a help as far as I'm concerned.