Linkifier Plus executing JS?

I'm using Linkifier Plus[1] and it keeps replacing 'undefined' with
'ftp://ftp.' anywhere it sees it. I am starting to wonder if there's
some way to get it to execute arbitrary Java Script, but I don't know
quite how to try to trick it; I would imagine all one word things like
alert('Luser!') would do it...

Anyway, thought that was interesting. Haven't probed into it deeper.

Linkifier Plus is built off Linkifier and Linkify Plus, so those may
also be affected...

[1] http://userscripts.org/scripts/show/6128

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