Congress writes bad laws all the time. So LinkedIn might be within their rights, but that doesn't mean they should have those rights.
It's bad for innovation to allow for selective discrimination like this. LinkedIn is perfectly happy to allow Google, Yahoo, Bing, and many, many more companies to scrape their content and use it for personal profit. Giving them the option to sue an upstart for doing exactly the same thing as Google is unfair and oligopolistic.
Letting established tech giants get away with this will slowly erode American dominance in technology.