Hi Guys,

I've been writing a fair few worksheets for a friend of mine that interact
with his trading software and allow him to auto trade.

I always believed they were just for him but I'm beginning to believe he
may be selling them on. I don't know, I really hope not.

I thought he was just coming up with wild systems to trade with and wanted
to test until a winner is found.

I'm no pro coder but a pretty decent amateur and would like to know if
there's a quick and easy way to know if my sheets are being used in
multiple locations.

I'm aware that any sort of 'phone home' code could be seen as a potential
threat, and that's the last thing I want to do.

I've thought about a kind of logic bomb that stops the sheet working after
a set number of weeks. Then requests a password to reset things which of
course he gets from me.

However, one single password isn't enough as he could easily distribute
said same password and I'm still none the wiser.

Any suggestions guys?

Ron