Stealth Camping on the AT?

Yes, very possible. People do it all the time including me.
What section are you planning on doing?
Some sections will be easier than others. Some places have rules and regulations about where you can camp:
for instance you will have to be 200 ft from a trail,water source,shelter/hut,campsite, and below tree line in the Whites. Ive heard of simular rules in other places.

Honestly I really want to do Maine, but am still in the planning stages.

I would recomend the 100 mile wilderness (Monson to Abol bridge). I have not done it myself but plan to some day.
Stealth camping will be ok there. Within Baxter you can only camp at designated sites-a highly regulated park!
It is not a true wilderness but it is supposed to be one of the most beautiful and by AT standards wild stretch.
The people on whiteblaze.net will be able to tell you much more that I.

I've stealth camped about 75 yards off trail in the Shennandoah National Park along the AT and never had a problem. I REALLY dislike crowded AT shelter sites and in the Nat'tl park you MUST be in the shelter. Thus the need to stealth camp.

But then, though I'v done hundreds of AT miles, I'm not the greatest fan of the AT because of its overuse. Just too many people, unless you like the "camaraderie".

Eric

I've stealth camped in the Georgia section with no problems.

I'll agree with Brian… if in Maine, the 100 mile wilderness is an awesome option. Make sure to have the 1lb hamburger while hiking it ;)

In the whites near where I used to live, I stealthed all the time, always near water. Peaceful to fall asleep to. However the opportunities in New Hampshire are not as plentiful as VT or ME IMHO.

The AT/LT in Vermont is also a great place to stealth, but a lot of the land during that stretch is private near the trail.

Stealth is quite easy on the AT, and is quite common for those who want to avoid crowds at shelters.

It's even easier if you hammock camp. You don't even need flat clear ground. There are certain places where it's not legal, but these are often the most likely places for some to truly "stealth" (like much of the Whites). The 100-Mile Wilderness would be very easy indeed to stealth camp due to the abundance of easy water sources and few areas where camping in not allowed (such as near Gulf Hagas).

Georgia is pretty easy to stealth camp. I hiked GA in late April; after through hiker mass. Spent 2 nights camped alone between Springer and Neels Gap and saw only a handfull (except at Hawk mountain shelter on day 2, a Saturday, many Scouts) of other hikers. Spent night 2 near Justus Creek and night 4 in campsites just off blood mountain. Very sweet! Watched the sunset through the trees; woke up to night ski full of stars! No other people around, nice. I avoided shelters most of time, although Low Gap shelter was appreciated on a cold rainy night, but discovered that only a 1/2 mile further and I could have had a sweet stealth camp. I think MD has many stealth camp possibilities, even though it is "against the rules",

Shelters are placed at logical mileage points 8 and 13 miles apart and always near a water source. Most also have nice places to tent. For example, I recently spent a rainy night in a great spot well protected by overhanging bushes and trees, yet onl;y a few yards from the Big Spring shelter in NC. There were only 2 other hikers in the shelter, I joined them for dinner and thoroughly enjoyed the company before returning to my tarp for the night. I have done this countless times along the AT. You will have no trouble stealth camping along the AT. There are only a few restricted areas. Here are the general rules for the White Mountains of NH: "The general rule is that you can camp anywhere that is 200 feet from a trail or water source, 1/4 mile from any hut, shelter, or established campsite, and is not above treeline."
Recently in NC I came upon two tents, so close to the trail, I could have easily kicked into them while standing on the trail, and their food bag was actually hanging over the trail. Unless an emergency, I found that a stupid place to tent. Animals use the trail at night, and why do you want people walking by so close?

I've camped right ON the AT…a decision culminated from a late night push, bad weather, and absolutely horrendous undergrowth consisting of a tunnel of practically impenetrable rhododendron. I was up and moving before dawn, so I wasn't in anyone's way…I think.

Anyway, as stated numerous times above, stealthing on the AT is usually pretty easy. Generally, between the times of stopping to set up at night and breaking down in the morning you won't see many hikers anyway. Unless you're in a National Park or someone's backyard there won't anyone out looking for rules-breakers anyway.

Just stay away from yellow rain flys!

Ya there are lot of places in AT for your kind of camping and also there are some restrictions.You can do it only with the permission of the authorities.

Camping

If you are doing Maine a hammock makes life a lot easier. Not as many flat spots up there compared to some place like Georgia or NC/TN.