I have implemented userID tracking via universal analytics as:
ga("set", "&uid", "'.<?= $userId ?>.'");
I thought I should be able to see specific user in reports, but it seems it is not possible to even show different users in any kind of report. I didnt find this option in analytics API either. I was hoping that I could track events created by this specific user.
Is it possible to track specific user in analytics report withouth creating custom dimension and settings userID as its value?
No. The user id feature is intended to recognize authenticated users across devices so it can generate cross-device reports. However Analytics will still deliver aggregated data only.
If you create ids to recognize individual users you not only need to be careful not to violate Googles TOS (which forbid to user personal data or anything that can be used for people outside your company to identify users), you also have to take into account different legislatures (for example where I live profile building is legal only with the permission of the user, and in fact in it's TOS for the user id feature Google requires you to get users consent before you track them via a user id).
So the free version will not give you user data (afaik with premium you can export data sets with the client id per user to Google Big Query, but GA Premium is a bit pricey).
来源：https://stackoverflow.com/questions/27059136/google-analytics-userid-tracking