When the term 'terrorism' is used in America, it usually refers to al-Qaeda or a related movement. However, the most deadly terror attack on US soil prior to 9/11 was the Oklahoma City Bombing, carried out by a right-wing white supremacists.

SPLCenter.org: Hate Groups Map

The Southern Poverty Law Center is one of the most prolific compilers of information on 'hate groups'. These tend to advocate violence of one form or another. The ones you've probably heard of include the Nation of Islam, the Ku Klux Klan and the Westboro Baptist Church.

So:

-Do you think domestic terrorism is a serious threat?
-Use the map and locate the hate group closest to you. Did you know they existed? Are you afraid?

It's true that it's easy to overlook domestic terrorists, whether it be individuals or groups set out to harm others.

Based on the history of domestic terrorism in the US I'd say it's not AS serious of a threat as al-Qaeda, but that's only based on what's been done by each group.

The total number of deaths caused by domestic terrorism is way more than the death toll from al-Qaeda. Individually though, no the groups are not as dangerous.

Should they still be stopped, yes. I did know they existed but since I never hear about them in the news I haven't focused much attention on them.

Most of the domestic guys never do anything. Obviously some of these groups are extremely dangerous, such as Earth Liberation Front and others. But in 2008, the vast majority of these guys just want a club to sit around and share their secret handshakes, make fun of other groups and eat hamburgers.

This reminds me of an excellent chapter in Freakonomics about how Real Estate agents and Ku Klux Klan agents are all about information power. This guy infiltrated the Klan, got all of the secret handshakes and words and wrote them into an episode of Super-man.

From this blog:
Kennedy thought of the ideal outlet for this mission: the Adventures of Superman radio show, broadcast each night at dinnertime to millions of listeners nationwide. [...] Kennedy began feeding his best information to the Superman producers. [...] And Kennedy told the producers the current passwords, agenda, and gossip emanating from his own Klan chapter… [...] The radio producers began to write four weeks’ worth of programs in which Superman would wipe out the Ku Klux Klan. [...] Kennedy couldnt wait for the first Klan meeting after the show hit the air. Sure enough, the Klannern was in distress. [...] At the following week’s Klan meeting, the room was nearly empty; applications for new membership had fallen to zero.

Comparing domestic terrorist to international really comes down to motive for me. If a bunch of people get together to promote white pride, black pride, Islam pride, etc... they are probably harmless. If a bunch of people get together to harm people that harm animals or harm Americans, they should be taken seriously.

This begs the question "What about OK City?" First, I've never heard what group they belonged to. Maybe they were in a group? Second, there is a lot of evidence Iraqi nationals were involved in the bombing with McVeigh, but that's probably for another topic.

The Klan's the closest to me, but I knew that already. A few years back the Klan had a march through my town. Really ****ing surprised nobody got shot that day, actually, considering the large black population in the downtown area of where I live.

Not all that surprising that the hate groups in Michigan are mainly either the Klan or Neo-Nazis. Michigan's pretty white, and pretty rural.

Wow, there's 3 hate groups in the city of Baltimore and two of them are white supremacist groups. That I find strange considering that it's a mostly-black city with pretty bad crime.

But the thing about these hate groups is that most of the time, even though they're still domestic terrorists they're not really a serious imminent threat until they do something heinous.