Perhaps the dems haven't done enough. but there are more examples to the contrary of your hypothesis. Deep blue California, where most of these IT companies are based, just five months ago passed an internet privacy law which precludes
all online companies from disseminating your private information without first informing the consumer and allowing the consumer to instruct them to delete it.
https://www.nytimes.com/2018/06/28/technology/california-online-privacy-law.html
This is perhaps a better example than the one I already gave, because not only is it not limited to ISP's, but if any democrats are truly beholden to Silicon Valley, you can be damn sure it would be the ones in Sacramento.
So, eh, maybe some dems are too close to Silicon Valley, sort of. But this is nothing like the bought and paid for relationship that the GOP has with, say, the fossil fuel industry.