Opponents are using cheats in C&C Zero Hour multiplayer games - how that???

Yesterday I played online and after 6 minutes lots of scud rockets hit
and destroyed my base. But there was no scud storm built. Then I
detected a mobile scud launcher - but it was at the opposite side of
the map - usually it cannot shoot over such a long distance - and the
fire frequency was incredible fast.

So I suppose the unit was modified (which became obvious when the
statisics appeared after the game: He had collected 9000 cash but had
built 56 units and 15 structures - he had 8 scud launchers - so this
cannot be).

If you change the ini file the game recognizes that so how is it
possible to cheat in Command & Conquer Zero hour and what can I do
against such people?

Greetz

Martin