Ask HN: The Unintended Consequences of Using FAGT Logins

We are working on a new website (directed at current and former students in the U.S. seeking public service loan forgiveness) and based on the research I've been doing, it seems like the community-building trend these days is to have new users register using one of their social media accounts logins as opposed to setting up a new account with the host site.

And I can understand why? Convenience for both the provider and the client. Spin off effects from associating with a recognized brand. The ability to piggy-back on a (purportedly) trusted source, NSA/CIA/FBI affiliations notwithstanding. But is this approach really in the best interest of our users?

One more piece of information -- we won't be handling any financial transactions but we will be keeping track of earned points (think frequent flyer miles) that our registrants can trade or cash in at a companion website we will be setting up to reward user participation.

Here is what I like to know: are there any unintended consequences from taking the path of least resistance; viz., allowing our users to use their FAGT logins? Or is it's turtles all the way... i.e., a non-issue I don't need to be overly concerned about?

Thanks for any insight you can provide... in the sense that it is still not too late to pull back and rethink what we are doing and why. Long term, we are hoping to benefit our customers, not harm them.