PPC Denial of Service - fundamental problem?

[blaze]

I have been approached and have heard of companies which are now providing services to 'click against' your competitors in particular search terms in order to discourage them from bidding.

How can this be solved, or will there just be an arms race against these people?

[Sanenet]

Guess it's just an arms race, coupled with stiff legal action by the part of the PPCs.