The data collected about us online is extensively used against us both online and offline. The multi-billion dollar industry around collecting and selling every scrap of data about you and your personal life didn't spring up because nobody was making money from it.
At all gets added to your dossier and it all gets sold and resold and used against you. You can't know what is going to prejudice someone against you, or what assumptions they'll make. Your browsing history can be a lot more relieving than your credit card purchases or your driving data. It can give them your medical issues, your sexual preferences, your addictions, your political views, your religion, etc. Just knowing the dates and times you're going to websites can tell them a lot.
The data collected about us online is extensively used against us both online and offline. The multi-billion dollar industry around collecting and selling every scrap of data about you and your personal life didn't spring up because nobody was making money from it.