Here at Ars we spend a lot of time writing about data caps—those ceilings on how much broadband data you can use before your ISP taps you on the shoulder and tells you it's time to pay more. Depending on where you live, these can range from "inconvenient" to "ruinous." For instance, consider the Middle East's Kingdom of Bahrain.

"My capacity refreshes on the 1st of each month and is depleted by the 12th," writes one Internet user there. "At that point my connection falls to 256Kbps (or if I choose, can maintain the same speed for 1 BD [US$2.65]) a GB."

"So while Canada's situation does suck," he adds, "I wish I was there instead of here."

As we note below, Canadian ISPs definitely cap data use. That country's Canadian Radio-Telecommunications Commission seems to think this is a reasonable approach. In fact, the CRTC is currently running a proceeding on how to "discipline" Internet usage in Canada.

Companies like Netflix are "putting a great stress on the Internet and there's no incentive for companies to invest in maintaining the Internet," the Commission's head Konrad von Finckenstein warned in early February.

That got us wondering as to how the crusade to whip broadband subscribers into proper behavioral patterns is going in other parts of the world. So here's a quick snapshot of the landline residential broadband data cap situation in the United States, Canada, the United Kingdom, and Australia. We'll extend this inquiry to wireless and other parts of the globe over the coming months.

The United States

AT&T. 150GB data caps will kick in for AT&T DSL customers as of May 2. First time over, you get a disciplinary message. Second time, "AT&T will send you a notice advising you that the next time you exceed your allowance—the third time—you will be billed $10 for each 50 GB of data over your allowance."

Comcast. The ISP announced its 250GB data cap limit in August of 2008. As with Comcast, the first time over, you get a call from the company. "If you exceed 250GB again within six months of the first contact, your service will be subject to termination and you will not be eligible for either residential or commercial internet service for twelve (12) months," Comcast's FAQ page explains.

Time Warner Cable. TWC abandoned its disastrous experiment with 100GB for $75/month in 2009. But the company still has an "acceptable use policy" that lets it reel in anything it experiences as "abuse" of its network, "including the use of excessive bandwidth." It has no hard caps, however.

Canada

Rogers Communications. Cable ISP Rogers Communications offers the following "generous" monthly usage allowances.

Ultra Lite - 2 GB

Lite - 15 GB

Express - 60 GB

Extreme - 80 GB

Extreme Plus - 125 GB

Ultimate - 175 GB

If you exceed these limits, you'll be charged from CAN$.50 to CAN$5.00 a gigabyte, depending on which plan you're on, with a maximum extra charge of $50 a month. Rogers lowered some of its data cap ceilings last July, just as Netflix streaming entered the Canadian market.

Bell Canada. Bell Canada's Essential Plus plan (CAN$24.95 a month) offers download speeds of "up to" 2 Mbps with a data limit of 2GB of bandwidth per month. Bell's top speed Fibe 25 Plan (25Mbps) sets the cap at 75GB. In the middle there's Fibe 6 (6 Mbps), with a ceiling of 25GB per month.

TekSavvy. Canada is in the middle of a long argument over whether to apply usage-based billing rules to smaller, competitive ISPs that connect with Bell Canada and Rogers for network access. At the beginning of this year the Canadian Radio-Telecommunications Commission (CRTC) was poised to impose metered billing on indie ISPs, with a 15 percent discount.

As a consequence, Ontario-based TekSavvy announced that it would impose 25GB a month data caps on subscribers, down from 200GB. But outrage over the CRTC's move forced the government to back down. It was in the context of this uproar that von Finckenstein's "disciplinary" remark emerged.

At present, TekSavvy offers residential DSL for CAN$31.95/Month at "up to" 5Mbps with a 300GB a month data cap, or with no data cap for CAN$8 more. Subscribers can also buy a cheaper plan with no cap at a slower throughput rate.

United Kingdom

BT. Right now, BT advertises the following data caps.

BT Total Broadband Option 1 10GB BT Total Broadband Option 2 40GB BT Total Broadband Option 3 Unlimited* BT Infinity Option 1 40GB BT Infinity Option 2 Unlimited*

But BT says the telco plans to remove these limits at some point in the future.

"As BT continues to invest in the network and network bandwidth we can now remove these restrictions and ensure the experience of the wider customer base," declared Mayuresh Thavapalan, general manager of Consumer Broadband at BT Retail. "On completion there will be no individual user controls targeted at atypical users on our BT Total Broadband and BT Infinity products."

Although Option 3 and Infinity Option 2 are advertised as unlimited, reports say they slow down when subscriber usage strays past 300GB. And the asterisks next to those plans lead to a caveat that they are "Subject to Network Management."

"Customers who are classified as very heavy users will experience significantly reduced speed at peak times," BT warns, "(typically 5pm-midnight every day but these times may change depending on the demand on the network) for a period of 30 days, or for as long as very heavy use continues. This applies to customers on all Options."

Virgin Media. Virgin Media's "up to" 10Mbps fibre broadband is actually pretty close to that—about 9.66Mbps, according to Ofcom. And it comes with "unlimited downloads," boasts the company.

We think you deserve more. So no matter which of our fibre optic broadband packages you chose, you get unlimited1 downloads. That means you can download as much music, as many films and as many photos as you want without having to worry about going over any kind of limit.

Ars readers are no doubt staring at the "1" next to "unlimited." It points to Virgin's acceptable use and traffic management policies. The acceptable use language bars activities that are "illegal," "unlawful," or "inconveniecing [sic] other internet users."

The traffic management policy notes that "at peak times we also slow down the speed of file sharing traffic—that's services like Limewire, Gnutella, BitTorrent and Newsgroup (Usenet) traffic. You will, of course, still be able to use these services, but downloads and uploads will take longer during these peak periods."

In other words, Virgin's unlimited downloads are subject to disciplinary limitations, albeit without data caps.

Australia

Telstra BigPond. Telstra's BigPond broadband plans come with caps, but when consumers reach their limit, they're not charged extra cash. Rather, as in Bahrain, BigPond slows them down. And we're talking about serious brakes here. After 2GB, the Turbo 2GB Liberty plan throttles from 1500Kbps (ADSL) or 8Mbps(Cable) to 64Kbps. Ditto for the 30Mbps Cable plan.

Those packages cost AUS$9.95 and AUS$19.95, respectively. For AUS$49.95 you can buy the BigPond Elite 50GM Liberty plan, which comes with a 50GB cap. For AUS$20 more, the 200GB Liberty tier comes with a larger caps and a "generous" 256Kbps speed after hitting your threshold.

Optus. Optus' high speed Internet plans have caps too, but subscribers are "disciplined" in a somewhat different manner. For example, the 30GB plan allows you to consume 10GB during "peak" times and 20GB during off peak hours, which Optus defines as so:

Peak data is for use between 12pm-12am AEST/ADST. Off Peak data is for use between 12am-12pm AEST/ADST If you exceed your off peak data allowance, usage will be counted towards peak data allowance.

Once subscribers reach these limits, the ISP drops their speed to around 8Mbps to 64Kbps. For the 120GB plan plug 50GB peak and 70GB off peak into that scenario. For 500GB it's 250/250 for AUS$69.99.

iinet. Australia's second largest telco ISP, iinet, offers a similar approach. "If you exceed your quota, we just shape your download speeds for the remainder of your billing month," iinet assures consumers.

So the ADSL1 Home1 plan offers 1500/256Kpbs upload and download speeds with a 5GB peak and 5GB off-peak data cap for AUS$34.95. If consumers go beyond that, their throughput rate is shaped down to 256/128Kbps, or 256/256 for other plans. Some plans include throttling discipline that goes as low as 65Kbps.

"At the end of your monthly cycle, the normal speeds of your plan will resume and your quota will be reset," iiNet promises. "We never charge excess fees on plans that include shaping. If the customer wants the service to remove the shaping before the quota reset, they must upgrade their plan."