First of all I would reccomend flagging the comment. Hover with the mouse over the comment and you should get this flag option:
You also have the ability to block people directly in the Origin client. Let me show you how:
1st way:
Go to the privacy settings and you can directly block someone. All user names in the Gallery are Origin IDs, so you just have to type the name that is displayed in the Gallery:
2nd way:
Go to the Friends menu and select "Add a Friend..."
You will then get this pop-up menu where you can search for people. I'm doing a search for my colleague EA_Rick here:
You will get a list with the name you searched for. Please click on the name here:
This will bring you to the profile. Depending on what the other user has chosen in their privacy settings, you can see their information like how many friend they have etc.
But you can also click on "Block User" here as you can see.