I am unaware of that site.

You may check

http://www.cut-the-knot.com/do_you_know/mul_eq.html

where there's an example of a similar argument

There's an outstanding book by E.J.Barbeau "Mathematical Fallacies, Flaws, and Flimflam" available at the MAA's bookstore (http://www.maa.org.), where you can find hundreds of much less obvious flawed arguments. Quite indispensable for a math major.

All the best,

Alexander Bogomolny