NYTimes: What the Repeal of Online Privacy Protections Means for You by Brian X. Chen:
What online privacy rules did Congress overturn?
Congress voted to overturn rules created by the Federal Communications Commission in October that required broadband providers to get your permission before collecting private data on your online activities and offering it for sale to advertisers.
How does that affect my online privacy?
The truth is, you never had much online privacy.
The new F.C.C. rules had not taken effect, so you probably won’t notice any difference. Internet service providers have always been able to monitor network traffic, see what websites you visit and share some of that information with advertisers.