"Copy and Paste this if you care"

[Kiwipinball]

I generally ignore them, but I think it can make sense to comment if you know this is an issue the poster has been dealing with. As someone else mentioned, I think a lot of people copy and paste because they feel guilty (they're probably also against cancer - most of us are - but it's not necessarily deeply personal), but if it's more personal for whatever reason, showing support is a nice thing (and probably a lot more noticeable than if you actually copy and pasted).

And those awareness campaigns totally spread awareness - of how annoying they are!

[Lula]

When you flood me with idle, spammy "awareness" material on Facebook or elsewhere, you're training my brain's filters to block your cause out as irrelevant background noise, which would seem counterproductive to raising awareness.