[Tuna-Fish]

> The pool would notice that certain participants contributions are conflicting with other discoveries, and ban such participants?

How? Or, you ban me, I sign up again under a different alias.

[gus_massa]

The pool can use a 2% fee for old accounts and a 20% fee for new accounts (for example, with less than 1 month or less than 10^x hashes calculated.)

[Tuna-Fish]

Fees cost almost nothing to hostile miners. With a 20% fee, they get 100% of their hashrate through the theft, and 80% from the pool. So long as you pay anything at all to new miners doing this attack is beneficial.

[marcosdumay]

But, you see, the attacker isn't mining anything of value under the pool, thus the pool has nothing to apply the fee over.

[eric_bullington]

And so few new miners would sign up. Which would be good.