Plot Summary/Details
I remember the basic plot of this one. There's a huge protest going outside of Stark Industries because of their military contracts. Stark/Iron Man is concerned that things may turn violent and cause people to get hurt. He has a trusted employee (I cannot remember the name, but I don't think it was Happy Hogan or any other major recurring character) stand guard across from the protestors to keep an eye on things.
I forget what Stark himself is up to during this time, but I do remember his goal was to keep things peaceful on all sides. The idea is the blue guy would be a deterrent to protestors from coming on site, but while also trying to avoid doing anything to exacerbate tensions. Sort of a one-man police line, if you will. The employee is issued a suit of armor similar to Iron Man's own armor. This armor is (IIRC) a uniform shade of medium to dark blue. It has many of the same powers, including repulsors in the gloves.
At first, things go well, but the person in the armor becomes increasingly "twitchy." I can't remember if it's out of a hatred for the protestors, or a fear he's not up to the task. Things turn tragic when he panics and blasts a protestor with a repulsor. The protestor is killed instantly (IIRC), and all hell starts to break loose.
Iron Man intervenes to stop his now rampaging blue-suited counterpart, taking advantage of a safety design he installed in the suit. Stark fires a repulsor blast at a spot in the blue armor's chest plate, which deactivates the suit.
The issue closes with Iron Man getting hit in the shellhead with a brick (and saying "OHHHHHH!") while the riot police announce they were moving in to put down the protest-turned-riot.
Timeframe/Publication Details
I'm positive the issue if from the 1970s, and probably from the earlier part of the decade. The protest story line would seem to reflect the real world Vietnam War-era protests of that time.