Why should private analysis of photos legally acquired be illegal?

If computers are legal and software is legal and photography is legal, it seems to me that running your own software on your own computers over your own photos should be legal.

I don’t like the implication either, but I think perhaps the thing we should be looking at is why it is legal for companies to take photos of us for commercial purposes without our explicit consent. I also feel it would be much more practical to regulate and enforce than regulating what algorithms they get to use on already-captured imagery.