This is a good question. I'll do my best to answer. For more detailed information please go to www.geocaching.com
Geocaching.com is a strong supporter of
Cache in Thrash OutA geocache is a hidden treasure and therefore is not and eyesoar. The odds are that on your way to work you will pass hundreds of close by cache locations but you will never see them.
A quick peek at your profile location, I entered Gloucester, MA into geocaching.com and found
roughly 70 geocaches in your vicinity.

In general a geocache is registered by the governing body of geocaching.com. Its owner is responsible for placing the cache within the posted guidelines. So I am responsible in making sure the cache does not litter, does not create an eyesore etc etc...
There are trinkets in every cache. On the island caches I tried to include items that would be useful for nearby kayaker or camper. I left such things as light sticks, mini flashlights ... My cache's are in a waterproof containter so potential contents can not leak out.
Every geocache has it's own web page profile. If a geocacher finds an issue with a placed cache they will log it in and suggest a maintenance. The cache owner gets immediately notified by an e-mail and is able to resolve the issue asap.
rb
Being totally ignorant of such diversions as "geo-cache-ing", will someone please explain the practice to me? What is the point of it? Are "leave no trace" ideals are disregarded here?