Is it normal to get get unexpectedly banned from subreddits?

I recently tried to post photos of myself in two subreddits. both showed they needed moderator approval before being visible.
But when I opened reddit today, I’ve found that I’ve been banned from both subreddits. I wasn’t given a reason.
I don’t really care about being banned, but I just wanna know if this is normal since I’ve never posted anything explicit?