Their 'fair usage policy' is laid out over 10 pages using Flash. You cannot copy the text or resize it.
Check it out yourself at:
http://www.celcom.com.my/cep...band/index.html.
Look for the 'fair usage policy' link.
I find it amusing that they regard 5GB / month as "extremely high usage". In that case, they should not be advertising it as "unlimited". Here's a screencapt of their policy:

See also:
M'sian ISPs' fair usage policies, P1 Wimax gotchas