Twitter Monitored and Controlled?

For the second occasion in these past two days, twitter has arbitrarily decided that I had exceeded my limit and was shut off from tweeting to "try back in a few hours." Now I am just a 53 year-old grandma from Pittsburgh, but am tweeting with many tweeps all over world, and many lately with Libya and liberal progressive information and ideas. I just saw a tweet today from fellow in Japan who said, walking around with big ideas in your head can be dangerous."

And no, I have no ideas of grandeur and am really nothing in this world, am not paranoid, am not influential with anyone. But why, after days of tweeting for hours at time prior to these Libyan FF Uprising, am I all of a sudden "over my limit?" Tweeting furiously during debt crisis last few weeks was no problem, but now that other countries with global implications are involved, it is another story.

Who is monitoring tweets, and who is deciding when and how parameters are set for shutting people off?

I see tweets from kids and radicals and crazy people all the time which are offensive and goofy and silly beyond comprehension, but mine with valid content to others in important situations are deemed "over the Limit" by somebody. Who is it and why are they doing it?

Someone who is somebody should investigate this. Social media is important tool for communication and collaboration in today's world, and we should all have free access to express our voices to anyone and everyone at all times.

I have always been skeptical of conspiracy theorists and paranoids and "big brother" scared y cats. And still am. America stands for freedom and it always will, and the spirit has not perished from this earth, even here on this hillside in Pittsburgh PA. No one can stop me from gathering information, thinking, and communicating in other ways. There is blogging, email, snail mail, telephone, person to person, person to God communication available and I will use them all until my last breath. But I still have a question. Who is monitoring Twitter and why?