Skill Drain rulings

Activate by paying 1000 Life Points. The effects of all face-up monsters on the field are negated while those monsters are face-up on the field (but their effects can still be activated).

The main concern I've come accross with skill drain recently is the "(but their effects can still be activated)." in the cards description.

This merely means you can pay the cost that is required for a cards activation, I.E the discard for snipe hunter, but you cannot activate his effect of rolling a die, and destroying a card on the field.

It also means, cards like stardust dragon and rescue rabbit cannot be stopped by this card. as both of their costs to activate their effects cause them to leave the field, where skill drain can't stop them.