What is SSSS? See the Wikipedia page:
https://en.m.wikipedia.org/wiki/Secondary_Security_Screening...
I went to the airport 3 hours early with no identification and told them the situation. They still printed my boarding pass and put SSSS on it. I went to the huge long line and I went around it entirely and went into the secondary screening room. They did a full patdown and entirely emptied my carry-on. It was no big deal and was done in 20 minutes, less time than I'd have stood in line. After that I boarded the plane and went home.
I've sometimes contemplated putting SSSS on my boarding pass with a red sharpie when there is a very long line just to get around it entirely.
Anyone that I'm aware has had issues, knew they were permanently of the SSSS list, knew what would happen, ignored it, and had minor issues; in case it's not clear to others, you got a one-time SSSS for not having an ID.
Clearly, given anyone might have issue and I've seen it happen, ("I swear, I was joking, I will never say that again; [as passenger walks away with law enforcement].")
Any rate, while I agree neither with the SSSS or for that matter, it's been shown that TSA offers no real protection via their owe audits - an SSSS flag has no meaningful impact yo my knowledge.
Most of the major conferences I'm sure have attendees listed (not a new practice - post-McCarthy's 'red scare' made it acceptable for both federal/local LEO to monitor protestors - but I'm sure it's way easier now and this dude basically painted a target on his body.)
My experience is that those with SSSS get through TSA screening faster and given they expect the search, don't have anything worth searching.
Clearly if you have an SSSS and create problems or provide surface for friction, then sure it's a pain, but then again, with or without an SSSS there's the potential you'll still have issues.
