Blocking is currently limited to nodes. It would be useful to be e.g. to block the author of a comment. Enabling this will require a fair bit of work to the module, since the current implementation is tightly tied to nodes.
The work is complicated by the fact hook_comment() doesn't support a 'load' op, so we can't easily load additional properties onto comments.
On the positive side, refactoring to support comments will make it easy to add additional objects (e.g., users).
Here is a preliminary patch. It's not working yet.
Comments
Comment #1
nedjoHere is a fuller patch. It's basically working, but I've just made an untested change towards enabling links on user pages as well as comments and nodes.
However, this patch would require a change in fasttoggle. Currently we can't add toggleable properties to comments. The patch here http://drupal.org/node/227582 would enable that.
Comment #2
nedjoThe patch at http://drupal.org/node/227582 was applied--thanks Konstantin! I'll update this patch and apply it when ready.
Comment #3
nedjoThis was applied.