One of our competitors constantly copies all our website content.
Now, I assume the trouble is to proof that we wrote the content first and that it is not the other way round.
I checked on http://www.archive.org, but there is nothing. Any other way to proof that?

FYI: We are a swiss company, so different laws will apply.

Solution: [Found later]
You can upload your content to this service and that they basically timestamp it.
https://myows.com/

Another way we found, is to just print out your copy/design, etc. put it into an envelop and send it to ourself (without actually opening it later of course).