Junk also tend to accumulate in rivers and lakes. Once it’s in there it’s out of sight, out of mind - and even if you know it’s there it is often difficult to remove.
When it finally gets cleaned up by bringing in the magnet or a barge to dredge it up or whatever, you’re seeing years if not decades of stuff that’s getting pulled out all at once.
The supreme court left it kind of vague in their ruling. The courts are supposed to decide, but for something like this no matter what the lower courts decide, any ruling would almost certainly get appealed up all the way up to the supreme court. So what is or isn’t an official act is basically boils to whatever the supreme court decides it to be.