Seeing the results is likely to make your beliefs less accurate, even if you know the information content is effectively zero.It might not be immediately obvious how bogus web polls cause harm. But if anchoring bias feeds into conformity or bandwagon effects, and that cycles into voter policy demands, we can move from bogus poll to "most people think X" to "Policy should be X" to "How can you oppose X, most people agree...". I think similar mechanisms work in bogus "cost of X" studies, eroding some voters' default liberalism by convincing them that they're bearing, through the tax system, costs actually borne by those engaging in the activity.
StatsChat continues in its Sisyphean quest to beat the stupid out of journalistic use of stats in New Zealand. Check the link above for fun and game in margins of error across three web polls. Forfty percent of Kiwis know these stats are bogus; shame it isn't eighnty.