Contemptible things to do with the infirm, part II. Invite an epileptic neighbour over for dinner, and fill your bath with warm water just before he arrives. Then, wait until he visits your bathroom, and turn on the stroboscopic lighting to induce an epileptic fit. With luck, he'll have a seizure in your bath and - hey presto! - you'll have an instant Jacuzzi. And, if he's still in the throes of a grand mal when you've finished bathing, why not chuck your dirty washing and a capful of Daz into the tub, and save on laundrette bills too? Film the event and you could even run an advertising campaign for your patent Epi-strobe kit on Channel 4.

I expected equal displays of callousness on Saturday night's I'm Your Number One Fan (C4), a documentary whose advance publicity suggested it would shamelessly parade a legion of the utterly nutterly before the cameras for our amusement. But, far from being cold-heartedly exploitative, the programme was a perceptive appraisal of the desperate way that some isolated and inadequate members of our society give a purpose to their purposeless lives by focusing on an unattainable celebrity, and then willing an emotional relationship with them into being. "Repeated attempts to communicate with someone who is unwilling to be communicated with" was how the phenomenon was described so, thanks to Reader's Digest mailshots, viewers already had a pretty good idea of just how vexing the problem can be.

I thought the porcine aviators would perform a victory roll the day I'd start feeling sympathy for DJ Mike Read, but then I'd reckoned without the enormous bulk of Blue Tulip Rose Read, his self-proclaimed wife. She boasted that she was "Mike Read's number one fan" (surely that distinction belongs to Mr Read himself?), sent him threatening letters, and made violent declarations of love to him outside the Classic FM building, though she insisted her behaviour didn't actually constitute stalking - which was technically true, but only because she was far too fat to keep up with the sprightly object of her desire. Although the woman was barking mad (literally, since she even woofed and howled along to his records), she was, curiously, more enthralling in her five minutes of airtime than her hero has managed in an entire lifetime of broadcasting: "I saw him outside the BBC, he was with Ed Stewart... Ed Stewart's breath stinks but Mike Read's got beautiful breath... I playfully tapped his bum - wooh! the electricity - and I thought 'this guy's for me.'" For his part, Mr Read philosophised that "love and hate are very close to each other" (not when I'm listening they're not) and, when he quoted Oscar Wilde's poignant line that "each man kills the thing he loves," I was momentarily touched. But then I remembered his hideous setting of John Betjeman's Myfanwy, and suddenly Blue Tulip started to seem like Mike's ideal soulmate.

Each stalker's fixation was unique, yet the sad progression was always the same: from admiration to obsession, then depression, anger, threats, and occasionally even violence. A cynical (equally crazy) agent offered this advice to celebs - "don't knock your stalkers, they're a sign of success" - then minutes later suggested the whole lot should be hanged, but I doubt if any of his advice would make Princess Di feel better about her demented follower, the German surgeon Klaus Wagner (even though she reputedly has a keen interest in having large organs removed from her body). Due to an unfortunate combination of influences - massive drug abuse, tabloid newspapers, and chapter XIII of Revelations - Wagner has become obsessed with the (probably correct) notion that the Queen would like Di to die, and promulgates his opinions at every opportunity, much to the exasperation of his long-suffering partner: "He got his nose broken in the prison chapel after he kept shouting that the Queen is the beast." Those Securicor-trained vicars don't mess about. But there was one ray of light because technology, which has largely created the problem, has now provided a quick means of tracing heavy breathers who use telephones to terrorise female victims. However, if you suffer from asthma like me, every call involves heavy breathing. Why, on a bad day, I've ended up in police custody after a routine call to Directory Enquiries.

Director Jaine Green and Producer Bernard Periatambee transcended the documentary format this weekend, combining style and content (the ransom note titles perfectly reflected the sinister subject matter) in a true work of art that deserves to win every award it's entered for. A flawless programme which simultaneously provided eloquent proof that tragedy need not be solely the domain of TV drama, and that the best comedy seldom emanates from Light Entertainment departments. Although, having watched a pilot of It Happened Next Year this weekend, LE departments seem to be getting pretty adept at tragedy these days.

VICTOR LEWIS-SMITH