These were based off of the blocks being logged. Either you griefed it, or your account isn't as secure as you thought, in which case it is still your responsibility.

 

Here: is the grief report that got you banned, in it the mayor of Cookietown made a grief report about missing water on the fishing tables. As you mentioned that you build fishing tables in other people's towns, I think that you must've recently built that fishing table and because of that, the logs were not cleared and you were banned for a crime that you didn't commit.

Unless Unknown or another moderator has some additional info to this situation, I will simply leave this unlocked for a Supermod+ to unban you, I am very sorry that you were unrightfully banned.

Unlocked for a Supermod+

 

So, after further inspection of the area, it appears that your story checks out for the fishing tables. Though this leaves me puzzled on what actually caused the destruction of the fishing tables. In any case though, you will be unbanned.
Unbanned
Locked.