Ideally, yes, we should use CC licensed images. We do use them for our blog.fshm.in & wiki.fshm.in
However, memes make use of the emotional attachment to existing content to convey a message.
We however, demand, lobby for CC licensing in all works with appropriate & fair compensation policies.
Generalistic and moderated instance. All opinions are welcome, but hate speeches are prohibited. Users who don't respect rules will be silenced or suspended, depending on the violation severity.