As long as those companies do not have any monopoly[1] and do not offer any public service, why not?
They are not free to snoop into information that isn't standard or reasonable. But if they aren't running spyware on my computer[2], they can decide whatever they want with the information my browser send to them.
[1] Do they? I'm not sure wether Linked-in has a monopoly as middleman in job searchers.
[2] How does invasive Javascript stands here? I'm inclined to consider that it's my browser's job to protect me, not theirs. But if they do some very unreasonable things, the blame is on them again.
They are not free to snoop into information that isn't standard or reasonable. But if they aren't running spyware on my computer[2], they can decide whatever they want with the information my browser send to them.
[1] Do they? I'm not sure wether Linked-in has a monopoly as middleman in job searchers.
[2] How does invasive Javascript stands here? I'm inclined to consider that it's my browser's job to protect me, not theirs. But if they do some very unreasonable things, the blame is on them again.