Is it possible to track your users in a privacy-friendly way? Absolutely!
Privacy-friendly product analytics software, like this one here, helps you to do just that. Fugu doesn't save or log any information that can be used to identify a single user (so called Personally Identifiable Information, or PII). PII includes IP addresses, email addresses, names, phone numbers and so on.
Privacy-friendly also means that events or actions shouldn't be traceable to single individuals. Therefore, Fugu doesn't track unique users, not even in an anonymized way. Wouldn't anonymous unique user tracking be safe? No, because at one point a real user needs to be mapped to the anonymized representation of that user. Whether that happens before sending an event to Fugu, or after, doesn't really matter. The fact that the mapping is happening in one direction, also means that there is a way to go the reveverse direction. Therefore, the best way to avoid this is not to collect the data in the first place.
You might be worried that by not tracking unique users you will miss valuable data. Don't be. Let's take a step back and ask ourselves: What is the the point of product analytics?
Well, the point is that you better understand how your users use your product so that you can improve it, making your users happier. What you track and how you interpret your data is much more important to understand your users than tracking unique users. Tracking unique users is not worth all the disadvantages it brings with it. You already get enough information from aggregated, non-unique data to get a great understanding of your product's usage. Unique user data is high cost and low impact, and collecting it won't make your product more successful.