Problems
A particular problem with BOMs is that when files (and sometimes even strings) are (quickly) concatenated, the BOM occurs in the middle of the resulting file.
Empty files (without text) are no longer empty (zero bytes).
Files that contain only the
ASCII subset of UTF-8, don't have only ASCII characters anymore (the BOM is not ASCII). This might cause some tools to break
She-bangs (#!/bin/sh) not possible anymore.
VBScript script files with BOM don't seem to run anymore.