That's a very old article though. I'm quite sure this is no longer relevant. A friend of mine lost both his parents in Afriqiyah Airways Flight 771 back in 2010 and I remember him telling me shortly afterwards he got very uncomfortable ads in Gmail about insurances and funeral services. In Dutch though, so it could be those keywords are not localized.

Apparently doesn't work if the words are just in your signature.

maybe a script that adds it automatically as white on white text ?

That, or install an adblock.