To pick one that came up recently, though, here's a discussion of one of the advantages of trust in a forum like this one, related to trolley problems and similar hypotheticals. Another one that comes up far more often is other people's willingness to assume, when I say things that have both a sensible and a nonsensical interpretation, that I mean the former.

It's not clear to me that these attributes are strongly (or even positively) correlated with willingness to "stick up" for a conversation partner, since typically this behavioral tendency has more to do with whether a person is socially aggressive or timid. So by doing that, you're mostly signaling that you're not timid, with "being a good discussion partner" a much weaker inference, if people think in that direction at all. (This is the impression I have of wedrifid, for example.)

What kind of alliances do you have in mind?

I didn't have any specific kind of alliances in mind, but just thought the question might be worth asking. Now that I think about it, it might be for example that you're looking to make real-life friends, or contacts for advancing your career, or hoping to be recruit by SIAI.