A three-month Perl programmer could write a program that adds similar 'viral' code to all of the Perl programs or modules or CGI scripts in the current directory. The biggest thing tachyon does differently is to use *DATA to store the code and seek to rewind the pseudo file.

Anyone who's capable of writing code that will search for files with a particular extension, open the file and insert a varying number of lines after the first line of each file is capable of writing something similar. Most people here could have done that within a few weeks of learning Perl. Several could have done that in their first week.

That's not to say there are better examples tachyon could have chosen :), but does his code give someone a grand weapon of ferocious power? No. We already have that. It's called Perl.