It's all right when I do it

Sockpuppeting is okay when I do it:
 * "Multiple accounts are an accepted part of internet culture! No need to be all uptight about it." (Collected in the wild by Macallister Stone)

It shouldn't be possible to hold someone responsible for stuff done online:


 * "I know it's up to the guy to defend himself but I'm kind of worried that the computers themselves are never questioned in these cases. I mean, it shouldn't really be possible to prove anyone did anything on the internet." (Collected in the wild by TNH)

(I'd say he doesn't understand what we mean by "circumstantial evidence".)

My behavior was within the rules I just made up:

There's a folkloric list of offenses users will sometimes cite when reprimanded, by way of demonstrating that their behavior fell within the boundaries of what's acceptable. Profanity and personal insults are always on the list of Things They Didn't Do. Other popular offenses they didn't commit can include name-calling, making threats, and direct attacks on individuals.

This defense gets hauled out when they're being criticized for more complex, structural offenses -- for example, constantly shifting the grounds of their argument, or failing to acknowledge supporting evidence cited by the other guy, or restarting an old argument that's been thrashed out and laid to rest a dozen times, or insisting that a discussion of some larger issue be focused on their own tiny area of it. Instead of addressing the actual point of the criticism, they argue that their comments were unexceptionable because they contained no profanity or personal insults.

Some related defenses include "Criticism is a legitimate part of online discussions," and "The fact that it's possible for me to type words into the comment entry box means I'm entitled to comment." Both are irrelevant, since the objection was to the quality of the commenter's arguments, not to their being critical, or the fact that the commenter was posting them at all.