Freedom of Speech Leads to Harrassment

Facebook. Some would say no big deal i have a Facebook page, i am a member of this group , so what?
I would like to share my story on how it is a big deal. I of course have a Facebook page. Not thinking it was a big deal, i also joined various groups one such group was NOM (National Organization of Marriage).
While i love stating my opinion i did not think it would lead to such harrassment, after all, this is just Facebook. I did join in on the forum about the issue of same sex marriage. My opinion and beliefs were stated (which i oppose)and of course i did get backlash from pro-gay activist. Regardless everyone has a right to their own opinion (so i thought)so i kept on stating my opinion. After awhile a few of the opposers got together and started looking up information about my employment and my family. They actually emailed my employer, the statements i made in the forum , hoping they would fire me because i was on the computer during working hours. Luckliy i am currently laid off, so this back fired on them. Next they looked up informaion (on myspace) about my daughter. They started calling her trash and making derogatory statements about my family.
I was not the only one they did this to. Others that opposed also got the same treatment and it did affect their jobs and personal lives.

Why can't we agree to disagree. No need to go to extremes. I have a right to state my opinion you have a right to state your opinion. Is it because i am Christian?