At the point of writing, there has been a number of reports that Maxis is having network problem. It is not a nationwide problem(for example only part of Ipoh is down) and appears to have started about 3-4 hours back(6pm).
Here’s some screenshots from Maxis users on Twitter:As normal, I don’t think Maxis is going to apologies or notify their customers regarding this issue. By the way, their “IMPORTANT NOTICE” page was last updated in June 2009. Smooth network, am I right Maxis?