An outlaw would be someone whose crimes are so great, that they have voluntarily placed themselves outside of the protection of the law - in other words, a person would not be prosecuted for killing them on sight.
The term developed during the early days of the Western frontier, when certain crimes, such as cattle-rustling - stealing a man's cattle - were the actions of these outlaws. In the western ranges, cattle were turned loose for long periods of time, during which they had to forage for themselves. Out on the open range, some of them would wander away from the rest of the herd.
Most people, finding another person's cattle in their herd, would let the lawful owner know about it, and arrange for the cattle to be returned. Rustlers, on the other hand, would take unattended cattle, often re-branding it to be able to claim it as theirs.
We, as Outlaw Bloggers, are declaring ourselves to identify with those people who the law will not protect. This is, perhaps, an exaggeration, but not by much - given the position of the Leftists, that un-authorized speech, writing, or thought will be punished.
I'm going to take on some responsibility for getting this blog back in action. I'm going to pledge to post 3 times a week, on some un-approved topic, from now until the end of 2019. Perhaps we can get this blog back on track, and lend our support to Unauthorized 1st Amendment Action.