Sending rude emails could earn you a place on the national register of sex offenders, after a change in the law that came into force this week. And you'll still get beaten up by IT support, sacked, and then lampooned in the tawdry free papers. It's just not worth it.

The amendment to the 2003 Sexual Offences Act means that offences 'not primarily sexual in nature' can be punished with a Sopo (sexual offences prevention order). So if you didn't before, you might want to think twice before forwarding a risque image or lewd message to a toothsome colleague. Want to impress a lady? Get your Mum to cook a casserole, and do some forward rolls and judo chops by the typing pool instead. (Only if you live in a 1970s sitcom, obviously.)

'Improper use of a public communications network' was already illegal under the 2003 Communications Act. In this case improper use refers to a message that is "grossly offensive or of an indecent, obscene or menacing character". Which rules out 90 percent of my email. (Er, just kidding boss. It's more like 75 percent.)

This week's Sexual Offences amendment adds that offence to the list of others that already qualified for a Sopo. Everywhere apart from Scotland, apparently. But as we know, all Scottish people enjoy only wholesome clean fun. That and frying inappropriate foodstuffs.

The law will now class as 'sexual crime' such activities as nuisance phone calls, obscene messages and emails of a sexual nature. Hopefully this doesn't mean the thought police are on their way, but it does mean that you should be doubly sure the recipient of any hilarious jape is going to get the joke. And then don't send it anyway.

Which, let's face it, is as it should be. There's little more enervating than being spammed with filth, some no-brain's idea of humour or unwanted sexual attention (clearly I'm going on hearsay for the last one).

A Sopo bans a person from the behaviour that got them into bother for a period of five years or more. Five years of not sending email may represent a productivity boost for some, but people issued with a Sopo are also added to the sex offenders' register, which places them alongside some very ropey individuals indeed.

So while it goes against the grain for a libertarian hack such as myself to promote such large-government policy, I've got to say I'm in favour. Electronic communication makes bullies feel brave, because they can harass from the comfort of their own bunk-beds, without wearing out their green crayons. Anything that allows decent folk to commune in peace has to be good. And because email and web-posts are almost always easily traceable, there's every chance the feds can hoover up and humiliate a few deserving cases.