Rule Utilitarianism. Big data

The Utilitarianism theory defines what is write and what is wrong by assessing outcomes. No matter what bad consequences take place, the most ethical choice is always the one that has the greatest good.

Big data falls under this theory just fine. While it's hard to give any precise guidelines, the example can be considered in the abstract.
On the one hand it brings us economy boost by providing more specific information, on another hand it affects on the privacy of consumers.

Examples of The Good

• Big data cuts business costs
• Help government to track citizens and prevent unwanted events
• Using big data improves company's pricing policy
• Allow competition with bigger companies
• Suggests to user more interest-related content 

Examples of The Bad

• Ruins people's privacy
• Add an advantage to those who have been shown as a more trustable person by doing nothing personal online
• Uses tons of computational resources and not necessarily provides correct results

Here, the pros totally make up for cons and it's safe to say that big data makes world better place (according to the theory). However, we all miss times when we had old school internet and nobody even thought to add his real name to his profile. Still, it remains to be up to a person. If one is afraid of being "watched" all the time or he simply doesn't want to, there are bunches of software to make yourself anonymous but in this case he will face all sorts of issues and inconveniences which makes it ethically controversy.