[somejan]

Funny. http://7393249866/ resolves to http://255.255.255.255/ in Opera (on linux), it appears to do saturating math for the overflow.

[Vektorweg]

It works fine in my Opera 12.16 for Linux (amd64).

[laumars]

Same here:

    $ uname -a
    Linux GFMPC-056 3.11.2-1-ARCH #1 SMP PREEMPT Fri Sep 27 07:35:36 CEST 2013 x86_64 GNU/Linux