Oh yes - I've been bullied online many times (not talking about PC). Adult bullies generally target those whom they envy or those who threaten them or their status in some way. And yes, if you disagree with them, they like to gang up even more.

Best approach is to keep them blocked and do NOT engage. Bullies thrive off the attention they receive and if they can get to you and know that they are getting to you, they win and are most satisfied.

Keep on blogging and ignore ignore ignore.