Well, one reason is that a lot of people casually assume that the baseline level of radiation in the natural environment is 0.0000000...., but it's not.
Uranium has been extracted from seawater before. It's not economically practical, but it can be done, because seawater has uranium in it already. Tritium is also already in there.
Issues of concentration at the point where it is put into the ocean can be an issue, but once dispersed this won't turn the pristine, 0.0000000...% radioactive ocean into a radioactive hellscape, it represents an impercetible percentage increase of what is already there. That doesn't mean we shouldn't think about the implications, but "thinking about the implications" shouldn't start from incorrect understandings of the nature of the current world.
Earth is an amazing environment. It does an incredible job of giving us a low-radiation environment, compared to most of the rest of the universe which ranges from "dangerous" to "radioactive wasteland". But it's not perfect and we are not at a flat 0 even here.
No one really does make decisions like that though. The world is not a lab where you can control all the variables. Nor can anyone have the breadth of knowledge to understand all relevant research. We just adopt a set of heuristics based on our own experience and understanding.
And here is a good example of this in action. The optimal way to connect a nuclear power station to the grid is with a big overhead power line. Except that you would have to build it in a scenic area. Millions of people have a heuristic that make them believe thag powerlines damage the environment. There is no scientific basis for that. But you put the cable underground anyway at huge expense. The objective is to generate electricity, not deploy an absolutely optimal solution. And a piece of infrastructure built in the world has hundreds of issues like that. The only solution we have to that is politics.
Nuclear is like a religious thing. No one is actually looking at facts and science, they just have belief that this is a solution or the problem. Look how conclusions from an expert panel are shrugged at as "nuclear is obviously the only right solution", no one cares whether those conclusion are based on science or not.
Personally I don't disagree that nuclear is probably needed at least short term, but it's not a a reason to ignore or deny the problems it causes, some of them are hard to solve, and probably some also even hard to anticipate.
A better implementation could be to perform a full hash (not CRC32 though; maybe even a byte-by-byte comparison) when the fuzzy hashes match, which is a small probability anyway.
No. CRC32 doesn't care what you throw at it. It is related to speed of building a "database", for lack of a better word, of the file. Instead of CRC32 entire file, you just get chunks of it, increasing the speed. However this approach it's definitely flawed as there are plenty of file types that have the beginning and the end identical, so only the readings/CRC32 of the middle section might be actually useful. But CRC32 has a lower space hence collisions have higher chance to happen.
The better approach might be, for same size files, to just Seek(FileSize div 2) and read 32 bytes from there. If those are identical with another file then start a full file comparison until one character diverges then stop. If multiple files are having these same middle bytes then maybe do, for each file, a full SHA256 and compare those.
Also, as other commenters pointed, you might have same info but meta is different (videos, pictures, etc) so that needs to be implemented as well.
I wrote my own duplicate file finder way back in the days.
I did the obvious trick of binning by size before trying to compute any hashes, and was mildly surprised to find how few out of my ~million files had exactly the same size.
For multiple files with identical size I just did the full file MD5, we only had HDD's back then and we all know how much they like random access.
I wrote one too, over 20 years ago. Still works, that .exe, even today. Unsurprisingly I was using CRC32 too. When I look at the code that is there I cringe, such is the mess there. Oh well, everyone has to start somewhere.
