Someone may actually read this, and it may be a little embarrassing, but I am partly doing this to gather my own thoughts.
The first social movement that I was a part of was the internet atheist movement, circa 2005. I remember when the whole /r/atheist "faces of atheism" happened, and I thought that had I been the same person as I was in 2005, I probably would have unironically participated. Back then, it was clear to me that religion caused great harm to societies and individuals, and also clear that religions spout lies endlessly.
I eventually left that movement for broader internet based forums (sci-fi based ones that included some discussion of religion/atheism, which eased the transition), and looking back there was a significant amount of elitism within the community. After I left, there was the whole elevator-gate thing, which seems to have drummed up a lot vitriol, which looks like a reflection of that.
There was a significant need to prove that my cause was superior. Nowadays, I liken the feeling to being in a new relationship, or finding a new song that you really like. You want to shout it from the rooftops and have others agree with you, and righteously smack down those who disagree. The desire for righteous rage is one that is very common, but hardly reflected on. It transcends culture and class. I may write about it later.
I cannot really judge people who are going through the same thing I did, and obviously people who share my beliefs but cannot voice them due to fear of reprisals are going through a fairly rough situation, but the movement as a whole smacks of immaturity. While I agree with the basic tenets of "being an atheist", and still talk to more active members of the skeptic community, I don't really agree with the movement's actions as a whole.
Contrarianism (and trolling!)
This is partly related to the above (as people involved in either know). This again feels like a very youthful thing to engage in. I'd almost automatically correct people's spelling or grammar. If someone said something I believed was wrong, I'd usually start with "well actually..."
I have a friend who starts almost all his sentences like that, and it ultimately has cost him a lot of personal relationships. Ultimately, whether or not the beliefs put forward are sincere, contrarianism is about feeling smugly superior to your conversational partners. Or perhaps it isn't, and you actually think you're changing people's opinions rather than "winning" conversations.
I did participate in the whole anonymous movement, as did a few of my friends. We went to Scientology protests and talked about the latest goings on in the movement. Our participation was rather lazy, and we wound up doing nothing particularly illegal other than pirating a large number of games and movies.
For a while, on multiplayer games, I did a bit of trolling along with the rest of the comrades. While it was intensely fun and satisfying (because why else would people do it), it was rather toxic to the game that we played. We didn't kill the game (obviously), but we did regularly kill servers by all joining.
Today, I tend to be more inclusive about playing games. Winning is important, but so is creating a community that people want to participate in.
I will say that I don't entirely disagree with this either. Bad/wrong ideas should be challenged and confrontational discourse is important for society to progress, but there is a time and a place for it (i.e. where it has a high chance of success or on a large scale). However, JAQing off at a trans-person isn't going to change any opinions and makes you look like a jackass.
This is a little bit closer to now. I was on tumblr for a bit, and took some of what they said seriously (they being the blogs my friends were running; I didn't really venture that far outside that). Ultimately, while I agree with some of their tenets, they were too extreme for my tastes to last very long.
I'm noticing a similarity in themes here. Wobbling from one extreme to another before I have a tempering of opinion.
Here are some more unfounded opinions that I'm not going to justify (but I may give examples if the mood strikes me):
I believe that a well designed representative democracy is the best design for a political system we have at the moment. However, it is utterly reliant on a well educated and well informed population for remotely good results.
I think that free speech is important, and also would rather that the idea remain distinct from the idea that you can say anything, anywhere. From part of the troll community, which uses free speech to justify some of its more egregious actions, political discourse is different to shouting "Fire!" in a crowded theatre or advertisers not being able to make statements.
I think that market forces are a tremendous tool for allocation of resources, but that natural (that is to say market forces without regulation) market forces cannot be ethically applied to some industries. Those industries are ones in which collusion or monopolies are very easy to create (e.g. intra-regional competition with little inter-regional competition), or industries that prey on particularly vulnerable users for repeat customers. That's not exhaustive, there are a few other cases. But for the supply of smartphones, computer parts, or food, market forces do a wonderful job at efficiently allocating resources.
I still don't believe in a personal god (or any god, really), but I don't think religion is a problem for a large number of people. I do, however, believe that politicised religion is extremely dangerous (see ISIS, or the deep south of the USA, or to a lesser extent Scientology). What the religion believes doesn't necessarily affect the tragedies its politicisation produces, but nonetheless it is often a harmful uniting cause within a society.
I believe in personal freedoms, but ultimately a society has a right to restrict freedoms it deems unhelpful to its own survival. A society is not a state or a nation, per se, and what freedoms it restricts is ultimately checked by the reach that it has. We cannot legislate or control people based on what people might exist in the future, but we can write laws assuming they'll continue existing beyond us.
And I've run out of steam right now. One meal a day. Apparently a packet of mi goreng is about a third of your daily intake of calories.
EDIT: I forgot to add that it is highly likely that some, if not all, of my views are wrong in some way. However, it is very difficult to operate on the assumption that I am wrong. And for the time being, it seems right enough.