I know six or seven guys who caught escaped Atlantics back when it was a much worse problem than it is today. Most were caught in the Salmon River, as it seemed to entice a good number up it for some reason, some pure speculation being they may have originally come from the hatchery on Big Tree Creek and were therefore somewhat imprinted as smolts. That's not been researched that I'm aware of however, so is pure spec.
Jeremy Maynard caught one in the Campbell one day while guiding some Japanese anglers. He'd painstakingly explained to them that if they caught anything they would have to release it so they were quite horrified when their guide killed the first fish caught, the Atlantic.
Gerry Mitchell, Rich Glover and another couple of guys from Sayward caught quite a few from the Salmon and the late great Bruce Gerhart and I cast to a small school of them one day but didn't hook any.
In the past 10 years or so the numbers caught by sporties seems to have decreased, reflecting the closer attention paid to such things by the farmers, as losing stock is not a good thing to have happen, particularly if you've been feeding them for some length of time.
Lots used to get caught on a few west coast streams near farms too, but I don't know how that situation is nowadays.
Take care.