There was a time when broadband from Virgin Media was uncapped, if you had the top-tier package. But the times, they are a-changing - the company is now introducing some modest capping on lines that have a very high rate of P2P use.

This, the company says, is because some users are spoiling it for everyone. It told Pocket-lint that 20 per cent of Virgin Media's total network resources are consumed by one per cent of users. And who among us hasn't been annoyed from time to time because our Netflix stream dropped to SD instead of HD, or whose ping during gaming was just too low?

Virgin Media thinks it can make everything better for subscribers by monitoring its network, and then capping only when it's necessary. What this means is that if the network is flowing freely, then you'll be unlikely to see your speed reduced at all. It will happen only if the network reaches the point where time-sensitive data is being slowed down. Peer-to-peer is not considered time-sensitive because you'll still get your files eventually, just possibly not at a rate of 10MB per second.

When asked if the firm would introduce caps for other video data, or big downloads, Virgin Media explained that downstream data is not the problem here. It has more than enough bandwidth, but the problem comes with the upstream traffic. If you saturate this part of the connection, then the packets that your machine sends to acknowledge the safe arrival of data can be slowed down. When this happens, despite a plentiful supply of bandwidth, your download will slow down.

P2P is obviously bad for upstream saturation, as a large part of it involves sending a lot of data out to a lot of people. And because downstream speeds are always faster than upstream speeds on domestic connections, demand for the latest TV show or movie will always max-out an upstream.

It's likely that this capping business will annoy some people, who assume that because they're paying £50 per month for 100Mb broadband they're entitled to max out their line constantly. Sadly, for this price you're going to have to put up with contention and caps.

The good news is that for around £800 per month you can now get an uncontended leased line to your home (depending on location) which will offer you a dedicated pipe to do your P2P file sharing on.

Caps will operate only during peak times (downstream from 10am to 3pm and 4pm to 9pm, upstream 3pm to 8pm) and you'll be slowed down only on that day - when the clock strikes midnight the cap turns into a pumpkin and you're free to start your downloading again. Upstream and downstream are treated separately and hitting the limit on one won't mean you get capped on the other, which seems quite fair.

The amount of peak time peer to peer sharing you can do before being capped is down to what Virgin Media package you subscribe to. For example, an XL customer with 60Mb broadband can download 10GB of P2P data between 10am and 3pm before being capped, 5GB between 4pm and 9pm. They can also upstream between 4.2GB and 7GB from 3pm to 8pm.

You can see how your specific package is affected on Virgin Media's help page. It's quite important to note that this change will affect all customers, not just those on the newly upgraded packages. However, Virgin Media says this will typically impact only around five per cent of its customers.

Does this worry you, or do you think BitTorrent users and the like deserve to be throttled at peak times? Let us know in the comments below...