I did not know this.
According to the FAA Aeronautical Information Manual, Chapter 7 (Safety of Flight), Section 5 (Potential Flight Hazards) paragraph 7-5-4 (Avoid Flight Beneath Unmanned Balloons), the balloons referred to are large surface area balloons capable of carrying payloads, instruments packages or trailing wire antenna beneath them (see: http://www.faa.gov/air_traffic/publications/ATpubs/AIM/aim07...).
As I stated before, the FAA does not regulate small amusement balloons because they do not present a flight hazard otherwise they would regulate them.
As far as litter, latex balloons are environmentally biodegradable as described here (see: http://www.partyfiestadecor.com/index.php?page=eco-friendly-...) and here (see: http://www.balloonsgalorelansing.com/environment.html ).
So if you are flying your aircraft in Western New York on July 4 and you happen to bump into my little balloon sharing the same airspace as you, give it a liberty wave as it goes by. :)