The thing to remember is that there's no such thing as online privacy, and any idea that you can remain truly private online is a fantasy.
From the moment you connect to the Internet, to the moment you disconnect from it, in some way or another your every move is logged and analysed, and a profile of "you" will be created somewhere.
Whether or not this can identify you as an individual is open to debate, and most companies will claim that they "anonymise" your data.
However, collected data is frequently cross matched with other online data, so if some person or company with access to that data was sufficiently motivated to identify you, then it's highly likely that they could.
That being said, unless you're a "person of interest", then it's unlikely that anyone would want to.