Whether they are knowledgeable or not is another matter.
I have seen patches with "13", "FTW", and "69" on a huge number of vests in my travels, along with "DILLIGAF" and various run patches and group affiliation patches from H.O.G. to AMA to ABATE, and most were worn by club members who had zero affiliation with 1%-ers.
American, Canadian (on Canadians), and State flags are common, too.
Theirs were AMA chartered clubs, veterans groups, firefighters, and the like, not to mention a slew of independent riders.
I think, frankly, that attempts to attribute universal meaning to individual adornments will lead to painting with too broad a brush.
There seems to be a significant effort by some here to cram everyone not riding on a crotch rocket in skin graft shorts and sandals into the world of organized crime. That just isn't so, but maybe that meme serves someone's agenda well.
BTW, the leathers are protective clothing, and have better abrasion resistance than virtually any other fabric. You can get other colors besides basic black, but those are expensive and generally not seen as anything but attention-getters if you aren't racing somewhere.
...maybe that meme serves someone's agenda well.
Makes me realize -- all memes, all templates, serve some sort of agenda ... never really thought of it before until your post. Conclusion: A meme or a template is a red flag.
I am of the persuasion that the Vise Grips were one of many tangential groups caught up in the sweep by the Waco PD, that are now experiencing the consequences of (at worst) guilt by association and are being painted with a broad brush. Fu(k that.