I second that. I mean how hard it is for anyone (facebook) to check source of a page and search for "like+jacking+ninja".
At least rename php files to "unicorns".
Other than that, here's my review for a purchase of this plugin.
Works just as described. I've acquired more than 1000 likes so far and plugin works flawlessly. I get about 1% of visitors jacked (which I find a bit low, but nevertheless).
It's a great plugin.
The problem might arise if users reports your page often as a result of unwanted likes.