Someone else wrote your posts for you - for which you claimed the credit.

Regardless of the fact that they plagiarized them from someone else - you didn't acknowledge that someone else was writing the posts for you.

I cannot think of any reasonable excuse why someone would get someone else to formulate ideas , write them down and then post them as their own work without acknowlegement.

If you can't write any of your own posts - then just don't post. Simple.

Stake your bitcoin address or PGP key on bitcointalk so if there is a long time where you don't post you can prove that you are still in control of the account.