Old fashioned 'internet trolls' don't exist on forums like this anymore. Trolling the old way simply isn't worth it any longer - because these people posts will be removed and their accounts banned anyway.
But there's a new kind of trolls occurring on some forums: people who actively insist that they they aren't trolls, but instead have sincere questions and expect people to follow up on the posts. Instead of posting threads with old-troll style thread titles like "If we weren't supposed to eat meat, it wouldn't taste that good", they instead post things like "How can a vegan diet be natural when it will make you nutrient deficient?", followed up by a post saying that they are vegans, but still think that eating vegan does't make sense.
It's of course easy to respond to threads like that, so who knows why they are doing it...
Most of these people seem to have a few of these things in common:
They state their undocumented facts as they were absolute truths - and try to give the impression that their 'facts' aren't up for discussion at all - usually in the thread title.
They are - whether they are actual trolls or people who just behave like trolls - usually not looking for existing threads about the topics they bring up (but sometimes post 'sorry if there are threads about this already'.)
They are usually very negative about something but often pretend to be 'positive, but worried'.
They sometimes post links to (an article, blog or YouTube clip stating things they seem to agree in (negative stuff about veganism), and don't comment it, but ask what others think.
They sometimes seem to register to vent - explain some horrible situation eg. with some person who is very negative about them going vegan and then ask if other have had similar experiences.
Some of them are cunning spammers who first ask some question, and then post a link to a site (their own!) which has the 'right answer'. This has eg. happened with some woman who ended up with promoting some product she sold on a site that happened to be her own...
Some of them just post a negative comment, some sort of attack on veganism, something negative about the process of going vegan or vegan food as such (eg "vegan food is so expensive"), but disappear and never post back after someone has explained to them they 'truth' is based on a myth.
They often log in from IP addressed which 'cannot be resolved' (this software shows the IP number and name (whenever possible) for all posts and all registrations).
They often post in the most read forums, regardless of what their thread is about, sometimes with a 'sorry of this is posted in the wrong section'.
Whether the topic is veganism (on this forum) or something completely different on some other forums, some of these people have a tendency to us their short time here to thrown in loads of topics in one thread, meaning that none of these topics will get the attention they deserve. Such threads are closed with a invitation to start new thread with one topic per thread, but this is usually followed up by... nothing. Neither trolls os pseudo-trolls seem to like in-depth discussion of any topics.
There are also a few situations of people who have been members on the forum for a while but which for some reason (trouble with sticking to the vegan diet?), suddenly post attacks on viewpoints most of our members share. In a recent case, one person wrote that she had been eating some animal products and didn't regret it+ would do it again (on cases which easily could have been avoided), and asked if that would make her a non-vegan. When the response from several of us was that since vegans don't use animal products whenever possible, (of course) she wasn't a vegan if she used animal products and intended to keep doing that, whereupon she called some of us 'vegan police' and wanted to have her account deleted. That's not trolling, neither is it spamming... it looked more like a case of someone who wanted to stir up some reaction or give other readers the impression that we/vegans/most of us are an unreasonable bunch of people.
The bad news for these trolls/pseudotrolls/spammers/dramaqueeners/troll-like posters is that this is a forum which for the most is a non-administrated forum. The days where we jumped into long discussions with people who are against veganism/vegans/ or think we all have a 'holier-than-thou approach are gone.