in Northern New York, I had one through the business, another person had three. http://www.secretservice.gov/money_detect.shtml There are a few different ways to tell so check with your bank.
20s were being made over in the central Maine area a few years back. I think they nailed the guys doing it… not sure tho.
You can also use a magnet to test for magnetic ink... Fold the bill crisply lengthwise so it stands off a table at a 90 degree angle and slowly move a magnet near the bill without touch it... A real bill should flutter slightly.