It seems to me like the principle should be similar. If a company has an exclusive-vendor agreement with an engineering-consulting firm for all its engineering services, that seems very much like the case where the company has an exclusive-hire agreement with an engineering union for all its engineering employees (just think of the union as a labor-selling firm). In both cases they've agreed to only purchase a certain category of services from a certain category of providers. I'd be somewhat amenable to banning all these kinds of exclusivity agreements (including non-compete, no-poaching, union-labor-only, exclusive-vendor, etc.).
Yes, a person does, but I don't think that question really gets to crux of the matter. I think the question is whether these companies were forming a cartel of sorts. Not a cartel of widget or oil production, but a cartel of jobs production. Its actually not clear to me that existing anti-trust law covers this case, and, from the DoJ's actions, it isn't clear to them either.
If the Justice Department was confident of its case, we'd be seeing a lot more publicity in order to put pressure on the companies involved. The fact that DoJ isn't raising a ruckus over this means they think they have enough to go to trial, but not necessarily win. In circumstances like these, where the law isn't exactly clear on the topic, both sides seek to settle because neither wants to be proven wrong in open court.
Yes, but it's a negative right, not a positive one. There needs to be a willing purchaser of his labor, and they have the same negative rights.
What was being done by the companies is an informal arrangement to make non-compete agreements exist even in the cases where the employee didn't sign one.
Notes: 1 - Pretty much the only non-competes upheld in CA courts are ones where the signing party sells a business or is a major partner.
Seems to me that these agreements might interfere with that, although the article does not seem to give enough information to tell exactly how they were structured.