I've been using it since I got my phone, almost 2 years now, and now recently I think that is really bad idea. I don't know is it possible for them to collect any kind of data or anything from just the fingerprint but how they are going with this technology I'm starting to get worried.
Thanks for any kind of answers or advices.

Most people have been using this unfortunately, and it's not a good idea. I mean, theoretically, this can be used for very serious creations of fake crimes and other things, which are pinned on someone. That is largely, theory and nothing else.

So long they do not have all your fingerprints, you should be alright. A sneaky method they use is that each model takes a fingerprint from another finger. One takes from the first or middle, while others take the thumb. Thumb is better to be avoided.

Uing fingerprint is better than Apple Iphone's using camera with ir sensor and getting your face tracked. Usually your fingerprint is recognized by your phone only. So it isnt as harmful. This reminds me of a story where a untrustorthy wife used fingerprint sensor to unlock her husband's phone by using his fingerprints when he was asleep.

Ok thanks for the help. I'm only using my index finger because it's easier to reach. And I don't have any extra fingerprints or anything, just didn't want to do that. Welp, I guess I'm fine.