How old are these scripts? Could be from Perl 4 days when "my" didn't exist.
I had scripts written pre-5 that had local, but when I was rewriting, I often would use my.
For online documentation, the links at perldoc: my &
local do a better job of explaining than I could.
They aren't from perl4...the date in the comments is actually from August of this year. I just think it's the programmer's unfamiliarity with the language.
There are other indicators that lead me to believe this. He doesn't ever use any modules, or even some of the standard lib stuff. For example, he's still packing socket addresses with: