Speak up and be heard!

What is acceptable behaviour at the workplace? What should you overlook and what should you take a stand against? At my ex workplace, i have to admit that the people there were different from any other place i have worked. They were manipulative, constantly seeking new means to make the next person seem incompetent and never taking responsibility for their lack of competence.
This much negativity was something i had never encountered so i guess you could call me "naive" because, as soon as i started telling every and anyone who cared to listen about my plight it seemed almost everyone had a similar story to tell about their workplace.
My first approach to all the negativity was to ignore them and try and keep the peace. I decided to never lose my temper, afterall, it was still an office and i didnt think bickering would be the best idea. Needless to say, that approach seemed like the worst idea at some point because it never got better! The more i tried to keep the peace, the worse things seemed to get and at some point i'm like, "What the bloddy hell is happening here!"
Well, i guess you can imagine how that turned out since i'm now at a different place. The thing is now, i fear i might be in danger of being labelled a villian because i've decided not to let history repeat itself and nip any form of insolence and rudeness in the bud before it blossoms into something caustic. The other day, there was an incident at work where a colleague i was pals with called me over the phone and was very loud and abrupt. Immediately i got into the office i cautioned him to never take that tone with me because i didnt appreciate it. When he was going to argue i cut him off and continued with business as usual, even approaching him when necessary like i hadn't just told him off. It wasn't because i wanted any form of controversy with him or because i dont like him but i feel that the earlier one draws a line and makes it clear enough, most people are unlikely to take the piss.
Since then, he's been very distant, maybe because he didn't see it coming and didn't expect me to be that abrupt but whatever his feelings, he has been nothing but absolutely polite and courteous so i guess my speaking up was not in vain.
There will always be people who will want to take advantage of you but even at the risk of being labelled the villian, you have to speak up. What do you need to speak up about in your life? What has got to change? At some point, we need to speak up and make ourselves heard or risk total disregard from those who think they alone have voices. Speak up! Xoxo