There are many people who do it, but the real question is, "is it legal?"
Most public land gives you 14-16 days of stay (per year? per month? they differ for each), then you have to move. Not just move sites, but move OUT of that public land all together. Staying 3-4 months would be in violation of the law and could just cost you more in tickets. Of course, you can move every two weeks to different free areas and be well within the law.
Now, there are places (Quartsite, Arizona) where you can purchase the permit for long term stay in the public lands and for a very reasonable price. Slab City is in a limbo when it comes to who owns and who's jurisdiction it is. So, you can live there for very long periods without much risk of the law. There are other places like that (limbo places) that people can stay for very long periods, but I'd say only if you keep a clean camp. Leave belongings laying around, and expect to be chased out pretty quickly... someone.
Then there is be elephant in the room that always goes un-asked.
Are there LEGAL places to do this near my place of work? Simply put, no. Free long term camping is only going to be "allowed" in the most out of reach places (like Slab City) which is no where near anything of value. Expect to drive long distances to get any groceries or water. It is the cost of "free".
So, if you want work online then you can live pretty much free-ish in some remote places without having to move too often. I am one of those folks, boondocking most days but I move often so never run into the stay-limit. I have boondocked in places up to 3 weeks, but never any longer.