gakked from
Regarding the irksome " share comments" button
A couple of friends have pointed me to a fix
The following line of code doesn't just hide the repost boxes it completely removes the option for everyone viewing your journal or community..
1. Go to Journal > Journal Style
2. Go to Customize your theme
3. Go to Custom CSS
4. Copy and paste
.b-repost-item {display:none}
into the Custom stylesheet
5. Save changes
Now not only can you not crosspost comments, but anyone viewing your account can't either. This doesn't get rid of the reposting option when you're making a new entry, but at least that one's easy to avoid."