No it's not and it's easy to simply put the person on ignore. That will block all the text and emotes. No one has to listen to anything if they don't want to. It's really that easy and engaging them just gives them what they want – ATTENTION.
Blacklisting someone on the public forum is inappropriate. What if someone did the same to you? Innocent or guilty, you may have to deal with the fallout: loss of friends and/ro increased harassment in Home and on the PSN. I suggest that you remove the PSN ID of the alleged offender and the images.
The primary means of reporting alleged offenders/offense is to use the report function in Home by pressing the SELECT button. Moderationh may not respond immediately, but they will get the report and take appropriate action (if needed).
If matters continue or get worse, you can come to this forum and send a Private Message (PM) to HomeForumMods. When doing so, you can send them the PSN ID of the alleged offender, the date, time, time zone and details of the offense.
Why risk getting into trouble because of someone else's bad behavior?