Certain tweets will never have consequences. The plethora of racist reactions to the re-election of President Obama last week - helpfully mapped here - will otherwise fall into the category of free speech created by the Founding Fathers and honoured and abused ever since.
Other tweets this week have been the epitome of the law of consequential actions and reactions. Israel live-tweeted its offensive into Gaza, complete with video and threats to Hamas, only to have the Alqassam
Brigades tweet back that Israel "opened hell gates on yourselves".
It's the 21st century version of dropping fliers on your enemies promising to rain down fire upon them. It is the insta-threat for a conflict that is already deadly enough for both sides without the need for war rhetoric in 140 characters.
But it's on British soil - or rather in Britain's Twitter ether - where the real consequences appear to be approaching. After the BBC programme Newsnight broadcast a story about child abuse at a care home, the twitterati, including some very prominent public figures, named the person implied by the show.
The allegations were false, everyone's apologised profusely, various people have left their jobs at the BBC and we're happy, right?
Lord McAlpine - who was falsely implicated and then named across both media and social media - settled on a pay out of £185,000 from the BBC for their part in the mess. But he's preparing to go after those who tweeted his identity. Quite right too.
There have been plenty of stupid examples of people questioned by police or even charged and convicted for admittedly stupid but otherwise harmless tweets or posts.
Earlier this week, police detained a 19-year-old man from Canterbury after he reportedly posted an image on Facebook of a remembrance poppy being set on fire.
As one Twitter user commented, "burning a poppy may be obnoxious, but it is not a criminal offence".
The authorities are overzealous sometimes with social media because it's so public, it's crazy easy to catch those responsible for acts and statements of stupidity. That might get their crime conviction statistics up, but it isn't doing much for freedom of speech.
However, just because Lord McAlpine's name is trending on Twitter because some people have worked out that he might be connected to a news story on child abuse, doesn't mean you can join in. I'm not sure you could even claim ignorance as bliss if you simply retweeted a link without checking or tweeted his name without a specific allegation.
At the time, you were part of a mob branding an innocent man as a potential pedophile. Why shouldn't there be consequences for that?
I saw a line of thought somewhere suggesting that since Lord McAlpine was a public figure, he should simply accept an apology and move on.
He was clearly defamed, by piecemeal identification by the BBC and directly by some Twitter users.
Some people in the digital age need to know that there have to be consequences and the rule of law, regardless of the capacity for good of social media. The freedom of expression it can give to individuals can be a great thing, and has been used to great effect in revolutions and campaigns for justice, fairness and equality.
But that capacity to speak is not an automatic protection if you break the law, such as defaming an individual.
The authorities may not have a sense of humour, or a sense of proportion to comments against whole religions. But specific comments against specific individuals - whether they be threats against
President Obama or defamatory allegations against a public figure - have to face legal scrutiny.
If Lord McAlpine wants to go after those in the Twitterati for their stupid and defamatory posts, then by all means. Will it have a "chilling effect" on Twitter? Give me a break - you can still say almost whatever you like on social media.
Just because a few people think before they send their next tweet doesn't make us any less free. It just makes us a little more responsible for our actions.