Old Hand's Space -- Blacklists have Bias

Blacklists Have Bias

I’ve already told you that you should not trust the data I give you blindly. See Zero Trust. I’ll give you an example of why blacklists are particularly biased and why you should be careful.

Preface

I live in Germany. For this example, let’s assume you live in Japan. I have no contacts in Japan. Let’s assume a large email provider with a server based in Japan, for instance, Microsoft.

Example

Since I have no contacts in Japan, the chances of me only receiving bad emails from that server in Japan are very high. It might land on a blacklist. In this example, it does.

You, on the other hand, living in Japan in this example, might have legitimate contacts that use that server. In this example you do. From your perspective, this server should not be on the blacklist.

Conclusion

In this example, the blacklist provided the correct outcome for me but the wrong outcome for you, and that was just based on where we both live. There are other factors that could produce a similar outcome when they are different.

Blacklists Have Bias

Preface

Example

Conclusion

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