Going legal is definitely a last resort.

This wasn't an accident though. I believe this was the change that overwrote everyone else's canonicals:

https://github.com/steemit/condenser/pull/3515

Whether you are posting to your own custom, wordpress, steempeak, a nitrous site like palnet.io doesn't matter. What does matter is that you are using a site to publish content that is not steemit.com