Successful hacks makes Codeforces better. Here are at least two reasons:

• A successful hack helped stable ProblemSet
• The defenders can quickly find bugs in their own code through the test provided by hackers

So hackers make contributions to the community, they deserve some contribution.

UDP1：

VLamarca's number of hacks(number of problem hacks) also a good suggestion.

If it does increases contribution, $$$\frac{100 x}{100 + x}$$$ contribution may be simple nice, where $$$x$$$ is number of problem hacks.

Fade hacks mentioned by Real_Father_Of_Ash is really annoying, it does know how to improve, but I believe that people who are loving codeforces and care about contribution won't do like this.

Really hope admin: MikeMirzayanov and geranazavr555 could take it into consideration.