Silver corrodes quickly in open air, that's why most supermarkets sell silver polish. IIRC, the culprit is sulphur.
I've had two gizmo failures due to silver contact corrosion, and sulphur was the cause. Silver sulphide is black and apparently a decent insulator (or poor conductor).
My local sulphur source is "sour gas" (Methane contaminated with Hydrogen Sulphide). The H2S is (mostly) removed in gas processing plants before entering the pipeline as 'natural gas', but some small amount escapes to the atmosphere.
OMG, who uses PNG files?! The compression routine is rubbish! I'm going to use this technology, but I'm going to convert the files to JPEG before I upload them. When people see how much smaller the file is that they have to download, they'll quickly move over to my way of thinking.
Those of us that need lossless compression, but we use SuperPNG, which has better compression.
The conversion to JPEG might be a disappointment - my gut feel says this torrent trick won't work if the data are altered by JPEG's lossy compression.