> I guess the issue arises when we got people working full-time hours but still being classified as an independent contractor.
Why though? There's plenty of contractors in other industries that work exclusively for a single client, often for 40+ hours per week. In technology in particular it's more common than having multiple concurrent clients (per person, not per consultancy).
In some countries there are limits on how long a company can employ a contractor. I can't find it at the moment but I think that here (Norway) it is something like four years. After that the contractor is supposed to be either let go or offered permanent employment. Perhaps someone more familiar with the rules could chip in, I've only been contracting for a short period.
I think the situation is somewhat similar in the US except that instead of a legal maximum the contract must specify an explicit end date after which there must be a break in employment.
Why though? There's plenty of contractors in other industries that work exclusively for a single client, often for 40+ hours per week. In technology in particular it's more common than having multiple concurrent clients (per person, not per consultancy).