A broad coalition of tech and telecom companies including AT&T (T), T-Mobile (TMUS), Google (GOOG), Apple (AAPL) and Microsoft (MSFT) met Wednesday with the Federal Communications Commission aiming to stop the consumer scourge of robocalls. However, in a lengthy report on the progress of the so-called Robocall Strike Force, participants acknowledged that they’re a long way from blocking the pernicious and rapidly growing robocalling industry.

Some 984 million machine-dialed “robocalls,” peddling everything from political candidates to vacation clubs, were made to cell phones in just the month of September, according to Hiya, a robocall blocking service. While some calls are merely annoying, others are used to perpetuate costly frauds.

Indeed, documents unsealed Thursday described a massive IRS scam that has taken consumers for more than $300 million. Some 61 defendants here and overseas used mechanized calling to reach thousands of victims, who were threatened with imprisonment, fines and deportation if they didn’t pay supposed tax bills with prepaid debit cards immediately. The tax bills were fake — the IRS doesn’t collect past due amounts by phone and certainly not through the purchase of debit cards. But the Justice Department contends that vulnerable consumers, many of them elderly, lost thousands to conspirators located both in the U.S. and India.

Scams via robocall are commonplace, according to Hiya, which estimates that more than half of robocalls involve some sort of scam or extortion scheme.

The calls, many of which are already illegal, are among the top complaints the FCC receives each year. And stopping them has become a priority for FCC Chairman Tom Wheeler, who formed the Robocall Strike Force last summer to clear both legal and technological hurdles that have stymied robocalling solutions in the past.

Though some progress has been made, the group noted that robocallers are constantly adjusting their techniques to thwart regulatory and companyside efforts to block them.

However, even sometimes ineffective blocking services are better than nothing. And possibly the most useful upshot of the latest task force meeting was that its members came out with guidelines for how consumers can protect themselves by using either tools offered by their phone companies or by downloading free software.

What tools are available to you? The answer depends on whether you’re blocking calls to a landline or cell phone, as well as which carrier you use. However, here’s the summary version:

Landlines

Nomorobo provides a free, third-party service that blocks calls from known robocallers. Though the service doesn’t work with every carrier, it’s available for users of VoIP services with AT&T, Astound Broadband, BroadVoice/PhonePower, Cablevision/Optimum, Comcast, Frontier, Sonic, SureWest, Time Warner, Ooma Premier, Verizon Fios, Voipo, Voip.ms, Vonage, 1-Voip and Wave Broadband.

Comcast customers need to go through a few extra steps to use Nomorobo, but they can also access the service by following directions on what can be blocked with XFINITY Voice.

Cox and Century Link offer some internal blocking features that consumers can enable (click on the carrier name to get to its robo-blocking page).

Cell phones

Hiya offers a free app for Apple and Android phones.

Windows device and BlackBerry users can check the CTIA Wireless Association’s guide to find free (and low-cost) apps that will work with their phone’s software.

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