If you haven't noticed it then perhaps it isn't so bad.
Yes, people do this frequently. It's not always obvious. I'll attempt to mitigate duplication by retweeting different tweets of my articles, or slightly varied content. I also keep a list of when I tweeted what, so it's spaced over time. There's services that do this automatically, but I don't use them.
For further actions, you may consider blocking this person and/or reporting abuse
We're a place where coders share, stay up-to-date and grow their careers.
If you haven't noticed it then perhaps it isn't so bad.
Yes, people do this frequently. It's not always obvious. I'll attempt to mitigate duplication by retweeting different tweets of my articles, or slightly varied content. I also keep a list of when I tweeted what, so it's spaced over time. There's services that do this automatically, but I don't use them.