Ever tried to find something that's missing online?
And that page pops up saying something like "404 page not found"?
Well it turns out they can be customised. In fact, Newsbeat has a pretty good one.
And we aren't the only ones, it turns out some of the political parties have a bit of a dark - and hidden - sense of humour. Here's what happens when you find a dead link on their sites.
The Liberal Democrat offering is more than a little scathing. The party changed its page after David Cameron confused Aston villa (who he supports) and West Ham in a speech over the weekend. Mr Cameron said he'd suffered a "brain fade".
Still, the old Liberal Democrat 404 wasn't much kinder. The party took a swipe at David Cameron's pledge not to stand for a Prime Minister a third time if he won the election.
Labour's efforts are slightly more subtle, but also feature a dig at the Conservatives. It can't be easy being in power with all these lost web pages having a go at you.
So what about the Conservatives themselves? Well we think they've been quite clever. No sarcastic remarks, but there is a quiz so the party can tell you how much better off you are under them.
Very smart, taking a broken link and turning it into an advert for the party's policies.
So how about UKIP? Well, the party likes to be seen as straight talking, and their 404 fits that bill perfectly.
In fact, most of the other parties we checked were the same; just a plain old "page not found" error. The Greens, Scottish National Party, Plaid Cymru, Democratic Unionist Party, Sinn Fein, Social Democratic Labour Party and Respect all went for the straight message.
Which is understandable, really, since no-one will ever really notice it's there as long as the website is working properly.
Nice to know there's a couple of hidden bonuses when it's not though.
Oh, and just in case you missed it, here's ours...