Guilt by association is invalid only in certain circumstances:
<assorted drivel>
Somebody posted a while back the question of
why Republicans are treated as idiots. This post exemplifies the reason: Complete lack of critical thought, or lack of value placed upon critical thought. Even the barest minimum of analysis shows
why "guilt-by-association" is properly considered to be a fallacy:
1) Strange how the criminal justice system does not ever charge a person for actions committed by friends or family. They may try a person for intentionally providing aid that was used to commit a crime, but not for being friends with a criminal, or for acting in a civil manner toward a criminal. The bottom line is that one is not accountable for actions (or alternately negligence) one did not commit.
2) It displays an appalling naivete to claim that no friendships occur between individuals of differing ethics, religions, political party affiliations, etc. I for one, despite being a militant atheist and “liberal” to the point of Socialism, nevertheless have one longtime friend whose beliefs may be placed within the purlieu of the religious right. Since such friendships do exist, one cannot claim that any two individuals...who happen to be friends...are similarly responsible for advocating a particular position.
3) Claims that friendship implies omniscience with respect to another's viewpoints are likewise extremely puerile. The human mind commonly elicits an emotional response when faced with disagreement. Because of this, it is frequently taboo in society to discuss potentially controversial subjects. Likewise, the vast majority of us who maintain friendships with those of strongly differing opinions do not always choose to debate, press, or elaborately detail those differences for the sake of avoiding strife. Without which, the full extent of another's beliefs cannot be known.
4) Beliefs are not static. One has only to show conversion statistics regarding religion or party affiliation to demonstrate this. The entire existence of rhetoric (in its classic definition as writing meant to persuade) assumes this. The entire existence of political campaigning presupposes this.
5) Friendships are not static. A person who was a close and personal friend for over a decade who then moves out of contact for a year and a half is then what? Still a close, personal friend. How well are they known during this absence? Similarly if an individual becomes preoccupied with a given task, relationship, or cause such that they have very little time to devote toward other friends or relationships then it is not reasonable to expect expansive knowledge of these others during that period.
To claim that guilt-by-association is valid, that one individual is necessarily responsible for and aware of the beliefs of another, is to deny these truths, and to spit upon the fundamental nature of skeptical inquiry.