I remember seeing lots of these when I lived in Silicon Valley. The snails climb the thing, then die and their shells stick around and bleach in the sunlight.
It turns out that Helix snails in California are literally descendants of escargots; they're not native, but were introduced to supply French restaurants, then escaped.
I took this picture on the Greek island of Naxos. Interesting to hear these guys do the same in the US. I had no idea they may actually be escargot, I was just being silly with the title.
Get a catfish if you develop a snail problem in your aquarium. They'll eat the eggs.
When I set up my 75gal. I had a stowaway in a plant that reproduced. Got a Pictus because I thought it looked cool. After a while I realised there were fewer small snails. Have a few left, but the catfish wiped out any eggs.