Thank you so much for your clarification. 

Indeed, the username sydesjokes looked familiar to me. (But the other usernames such as vapenation/fiftysats/superheroes appeared alien to my eyes.) 

Now that I know sydesjokes is to be avoided, could you get me out of the blacklist? I myself am a "rule of law"-based person, and I'll deeply appreciate your helping me. 

You're the best! Cheers! Peace and blessing!

No, it's weird. I didn't upvote all of those posts. (I took another look at the link).  They'd probably used my posting key through a third-party app. 

Could tell me if my account is still upvoting those posts? If so, how can I proceed with stopping these upvotes?

Edit: I remember going to steemworld(.)org to remove all the third-party apps from my account. Some months ago. So I am optimistic that those questionable upvotes had stopped ever since.