Version 7.0 of Opera was launched last week but immediately attracted flak because the former version, Opera 6 SDI had mixed attributes which allowed users of non-Windows PCs to join in the smurfing fun.
The core essence of Opera 7 is based on the Microsoft Windows platform which is really cheesing off users of graphical user interfaces other than Bill Gates' blend.
What they're concerned about is that the core of Opera is developed on Windows before it's ported to Linux and other OSes, making it hard for everyone to throw their oar in.
The online petition starts here, but there's more to the Web campaign than just that.
A "blog" has also started here, and there's a forum on Opera's own site with some pretty vehement stuff too, which you can find here. ยต