So?  This is not new.  
People don't seem to realize that even before facebook and google, even well before the internet, the same sort of thing was done through credit card information.
And before that, if you ever filled out a little card at a trade show or got a subscription to a trade magazine, your name went to a 'mailing house database' and you were in there.  
If you ever bought anything and got a receipt, chances are, your purchasing information, from which can be derived your buying habits, were all transmitted from that cash register to a regional data bank, and on to a bigger data bank, within a day's time.  Every booming retail company kept track of everything you bought.  Hi, Welcome to 
Walmart.
Most of their efforts, however, don't pay any attention to WHO bought the item.  They could generally care less.  Often, as the information moves along, the name is even replaced with a transaction number that is randomly assigned to each SALE, not to each person.  Their interest is generally not in individuals but in transactions.  Their interest is in how many people in a month bought bananas, how that compares to last month, and last year, and the year before, and do people buy more bananas in Detroit than they do in Skokie.  So they know how many bananas to buy, where to send the surpluses, what to advertise, etc.
I worked as a clerk for a 'mailing house database' company and it had milions and millions and millions of name, address, phone numbers, and a person's interests, purchases and such.  
That company, could, for example, go through all their information, and then sell to an MRI company, a list of several thousand doctors who don't have access to an MRI locally, who would be interested in buying an MRI machine, their income, their interests, name, address, phone, the whole nine yards.  It was called a 'targeted mailing list', and there were companies all over the world doing that.  With the crumbiest, most outmoded computer hardware and software imaginable, the computer people complained about it endlessly that it was like driving a Model T Ford.  Nothing real fancy needed.  
Much of THEIR interest wasn't in targeted mailing lists.  Their biggest customers were trend finders and market finders.  For example, how many people in the midwest expressed an interest in the MRI machine.  Just to get a general idea, is it worth having a regional sales office there, or even more currently, should we close the midwest sales office because the demand just isn't there.  So for the same reason, a lot of data they sell, has no individual names on it at all.
Health information, on the other hand, is extremely spooky.  Because of HIPPA, most of the medical information has to now be extremely anonymous.  Names are replaced with a random number.  You can't even say, there is a patient X in the midwest with this rare disease, because it would be easy to connect the dots.  Medical data that gets sold or re-used is actually very very interestingly handled and the rules are very strict.  
And yes, I suppose that even prior to the Patriot Act, there were other provisions for the government to appropriate information about an individual.  That's the price one pays for having the ability to detect crimes, terrorism, etc.
Facebook and Google have made it so it's cheaper and easier to get information about more people, but this 'issue' is not anything new.  At all.  
Can this information be misused?  Yes, information has been getting misused since information first existed.  Will it be used against ordinary citizens?  Unlikely.
There is a sort of 'zenophobia' of technology that people have, that I think is completely and entirely unreasonable.  They often say 'oh no!  Some new technology!  Now I won't have any privacy!  Big Brother is watching!'
The bad news is, that it doesn't require 'new technology' at all, and that it has been going on for a very, very long time without any new technology.
The good news is twofold.  One is that it is not cost effective to use the information to catch people who have chickens in their backyard, or are doing many of the ordinary things most people do - pay something late, make mistakes on their tax returns, bawl out their neighbor.    Two is that from time to time, the information helps someone catch real criminals, people stealing your stuff, people committing financial frauds.
The bad news is that people get the feeling they have no privacy, NOW.
Well the bad news is also, you never did have any privacy, not in the sense that most people think of it.  But also, that sort of privacy not being there, has little effect on the average guy.  But be advised, there is no need for complicated software or web sites.  If someone wants to know something about you, all they have to do is search public records, talk to your neighbors, etc.