Someone argues that a specific regulation is poorly designed. The reply comes back: "so you think we should have no rules at all?" Nobody said that. But the extreme version is far easier to defeat, and once it is on the table the actual argument quietly disappears. That substitution is the straw man, and it is probably the single most common way public disagreement fails.
What makes it worth taking seriously is that it usually is not cheating. Straw men mostly come from misunderstanding rather than malice — you encounter an unfamiliar position through its critics, or through its least careful advocates, and then argue against the version you met. Social media accelerates this brutally: the most extreme statement of any view travels furthest, so the version most people are exposed to is genuinely the weakest one.
The tells are learnable. Watch for "so you're saying…" followed by something notably more extreme than what was said. Watch for a specific claim being answered as though it were a universal one — an objection to this policy treated as opposition to all policy. Watch for the nutpicking manoeuvre, where the worst advocate of a position is presented as representative. And watch for the version of a view that has no defenders at all: if the position being refuted is one nobody actually holds, something has gone wrong upstream.
The remedy is the steel man, and it is a discipline rather than a trick. Before responding, state the other position so accurately and so strongly that someone who holds it would say yes, that is what I think. Only then reply. This costs something real — it often reveals that the view is more defensible than you assumed, and occasionally that you were wrong. That is precisely why it works, and it is the standard every page on this site is written to.