We need to be careful not to read too much into this data without context. "Liking" a fan page used to be a much lighter thing before the FB interest graph became interwoven into other applications & this new search feature.

I used to "like" friends fan pages without much thought, if they asked me to. Re: Ashley Madison, there are married people who work there and will choose to "like" their employer. This represents a small number of users, but is meant to show that there are legitimate use cases.

Once people start to realize that "liking" something is a fundamentally public act, this should be less of a problem. There's a huge difference between being a person "who likes Ashley Madison" (which I am not) and being a person "who has made a public declaration of liking Ashley Madison" (which I am also not).

Or, to be even more reductive: public declarations are public.