And sometimes those snotty or malicious tags can be intentionally attached to a perfectly respectable thread too with the intent of repulsing people from joining in. That's the unfortunate downside.
Our faithful, competent, and quite terrific programmers for the site do put a great deal of faith in the competent and mature prevailing on A2K. Unfortunately, I sometimes think they fail to allow for a small but active number of trolls who intentionally try to make trouble for other members or just in general.
You don't know what we put faith in. ;-)
The big update over the last night and today wasn't to put tags under the topics on the topic grid, but to address this issue where it was too easy for one person to make irrelevant tags. Showing them under the topic grid was just a cosmetic tweak we made once the data structure was the way we wanted for the anti-abuse fixes.
Before, one person could tag something and it would have more of an effect, now the aggregation points only work off the top 5 topic tags. For example, anyone could tag a topic "politics" and it would show up on the politics page. But now it has to be in the top 5 to show. Additionally, the aggregation points like related tags now discard the tags outside the top 5 so the irrelevant ones are already showing up a lot less in the tag clouds.
I have no faith in users never trying to abuse the tags, and some users are always going to leave irrelevant tags, insulting tags or just plain silly tags. All of this crowd wisdom worry would be a lot less of a concern if you guys understand that we aren't counting on the whole community to use things like tagging and voting the way they should, we are just counting on more of them doing so than not doing so and our ability to make code to catch the bad use as a statistical outlier.
So if you want to combat that kind of tagging, just tag topics. If you see an irrelevant tag on a topic just give the topic 5 relevant ones and it may remove the irrelevant tag. If two or more people do so it is much more likely to "fix" the topic tags.
We also implemented IP filtering and plan to start more flood control to curb the bad use even more. We'll also start filtering nonsensical tags (like a search stop list where "the" and "and" are not relevant) and even giving weight to users so that the ones that consistently use irrelevant tags will have their tags only count for themselves and not have any effect on the site.
But it all comes down to something pretty simple, if more good use is happening than bad use we can very easily make code to prevent the abuse. And we'll also do things to dramatically increase the good use of tagging (like enable an option to tag topics as you are replying to them, and giving tag suggestions based off other user input to concentrate the tagging on the more relevant ones) and even basic semantic analysis of the topic texts themselves (simple example is that if a thread is tagged "hot gay sex" and the topic is about Obama we can programmatically give tags that seem to be about the topic more weight than the ones that don't).
We have no faith whatsoever in the individual user or the totality of the user activity. We do have faith in that there are more users using the site in ways helpful to the rest of the community than users using the site in ways disruptive to the community and as long as that is the case it won't be too hard to have the community activity minimize the effect of the disruptive users.