There's something about trains that makes me feel like an adult. Combine a commuter train with a paper cup of coffee and I'm overwhelmed with a sense of being an important and accomplished person, on my way to do something meaningful and significant.

It's always winter in these kinds of situations, it seems. One of my first memories of really feeling like a grown-up is a purely evocative sense memory of getting off the Skytrain in Vancouver at Granville street, wearing a long navy blue blue wool coat (second-hand, naturally), carrying a shoulder bag and a cup of coffee, and being swept along with all the business people on their way to work. I'm not sure when this memory dates from, but it is pretty powerful.

I don't take trains very often, and I've only ever for one brief period of my life used a train as my daily commute. I wish I could take trains every day, actually (we are considering moving, so this may come true), but I always seem to end up living in other circumstances.

In South Africa and the Middle East, it was pretty much impossible to cope with daily life without a car. Obviously, lots of people do cope, using taxis, busses and informal public transport, as well as walking and bicycles. For someone with a white-collar job, though, it can be hard, and in Dubai, living in university-issue accommodation in a neighbourhood without busses, it was hard and expensive to not have a car. My colleagues without cars relied heavily on those of us with cars, which creates its own set of issues.

Since we've been in the UK, we haven't had a car, and in fact, neither of us is now legally allowed to drive. We only miss it sometimes. Getting across the country by train is a pain (up and down is a lot easier), and it would be nice to be able to rent a car and go camping somewhere. We are working on it (or Martin is), but we really don't want to own one. I look at cars now, and think, weird objects, why would you want one?

But I still want to ride a train.

I'm not sure how I feel about the #IamSpartacus campaign on Twitter.

On the one hand, freedom of speech is important, but on the other hand, threatening to blow up an airport - how stupid can you be? I don't actually think it's about Twitter, really, either. I know the campaigners believe that Twitter is being singled out, and this is some kind of blow for free speech on the Internet, but I'm sorry, I don't. If anything, this shows that Twitter is just like any other kind of speech, and there are some things you should think twice about saying.

Like threatening to blow up an airport.

Or asking to have someone murdered.

In his defense, Gareth Compton has called Twitter a "a forum for glib comment" and asked "Who could possibly think it was serious?" Except that plenty of the stuff on Twitter is serious, and should be taken seriously. The irony of a campaign on Twitter to defend the frivolity of tweeting cannot be lost on everyone, surely.

Going back to the original tweet, from Paul Chambers, I find it hard to be sympathetic. I mean, come on. Yes, we know security is ridiculous, yes we know the police overreact, so why the hell would you provoke them by posting something like that? And really, if you want to campaign to protest the expansion of police powers and the erosion of civil liberty in the name of the "war on terror" (and I sure as hell do) you could do far better than defending some tosser who was pissed at an airport for being closed by weather.

How about campaigning for the rights of the more than 100 000 people stopped by the police under stop and search laws last year? Of whom only 504 were arrested, and none of them for terrorism-related offences, which is what the stop and search law was created to prevent. How about walking into every police station inteh country, ringing the little bell, and saying "I am Spartacus". If nothing else, it would be a lot more interesting to see than thousands of tweets threatening to blow up airports.