I would strongly advise not using twitter if you are looking to re-affirm your faith in humankind.
Having said this I do sometimes use it - mostly for checking traffic news which seems to be updated on twitter far quicker than elsewhere. I also sometimes use it to check out things happening locally, again it is easier to go to twitter than the various websites to search for local events.
I am over 40, so the whole "put your life on twitter" thing leaves me a bit mystified. Some of the more idiotic tweets about cyclists have been from young men (and often, women) who appear to have no concept that what they are broadcasting to the world at large and what they say can be captured forever. To the point that one young woman who was particularly disparaging about cyclists wondered where all the cyclist tweets had come from and was somewhat affronted that strangers could respond to her inner "thoughts". It clearly hadn't occurred to her that her twitter account isn't private. On a more general note it amazes me that people will put their whole life on social media in a way that means they can be tracked down by a few google searches. This has just happened with the lovely gentleman who said he had knocked down a cyclist - he suddenly was confronted with the fact that someone had tweeted his employer's name and phone number.
I watched a programme when I was last in Brazil where they set up a "mystic" tent and invited the general public into have their lives read. The people were astounded when, just by giving the "mystic" their name, the town where they lived and their age, he was able to recount their life story, their family members, and latest events in their lives. Of course the mystic was rigged up with a microphone and earpiece and behind him were a group of researchers giving him the details of the person by trawling social media in real time. The programme had a serious point - if a researcher could find this information in a couple of minutes so could anyone looking to target fraud or worse. In a country with fraud and violent crime issues this could be very serious.