Archive for the geek Category

Last year, Matt Flick and I presented at both Blackhat DC and Defcon 17 about our Cross Site Scripting Anonymous Browser (XAB for short). XAB allows for anonymous browsing fueled by sites vulnerable to XSS. The tool/framework really had no other purpose than to finish the statement of “wouldn’t it be neat if…”.

All in all, it was a fun research project to expand and extend unintended functionality present in web browsers in an interesting way.

Here’s a link to the video of our presentation at Defcon 17: XAB Defcon presentation video

XAB can be downloaded at


A while back, I reviewed the 3m Privacy Filter. I’ve re-posted it here primarily because I’m still very surprised it’s use is not nearly as widespread as it should be. This review shows photos of the 3m Privacy Filter from all angles so you can truly judge it’s efficacy.


Every telecommuter needs to leave the house sometime. Maybe to get some fresh air – maybe even get a little work done at a local coffee shop. While at the local coffee shop, sipping a latte, crunching numbers or authoring a book, you may get that uneasy feeling that you might not be the only one crunching your numbers. Do you prefer to refrain from putting your sensitive data on display for passersby and nosy onlookers? Have you seen the silly 3M commercials during the CNN morning news and are curious if the 3M Privacy Guard actually works?

If you answered “yes” to either of these questions, read on. The 3M Privacy Filter may be useful for you.

The 3M Privacy Filter is marketed towards those whose work may require using a laptop in public places. This includes telecommuters who prefer to work in a public wireless hotspot (era Bread) as
well as frequent business travelers who often work on sensitive information in airplanes and trains.

3M’s marketing literature makes many claims of its performance. In this review, I will attempt to verify or deny those claims. Additionally, I will offer input based on my usage of the 3m Privacy Filter over the past few months on a 15.4″ widescreen Macbook Pro.

The 3M Privacy Filter promises the following:

  • Narrowing of the viewing area so the screen data is visible only to those directly in front of the monitor
  • Performs without distortion
  • Reduces screen glare
  • Guards against scratches
  • Unobtrusive design does not interfere with speakers or monitor controls
  • Easy to attach and remove – can be left in place when laptop is closed

Overall design

The 3M Privacy filter mounts to the laptop screen with clear plastic mounting tabs with – you guessed it; 3m adhesive. There are a total of 3 tabs used during this installation. As suggested by the included mounting instructions, two were placed on each side of the screen and one at the bottom. After several months of use, the mounting tabs are still firmly attached and have not degraded in performance or aesthetic appeal. There is a small round cutout at the top of the Privacy Filter. This is to facilitate easy removal. While it is quite apparent in the photos, it is not a distraction. The largest issue with these mounting tabs is that the privacy filter bows inward when closing the laptop. This may be less of an issue with a smaller screen, however the behemoth 15.4″ Macbook Pro screen causes bowing in the filter upon closure. This bowing of the filter does not affect performance, but only presents its self as an annoyance when closing the laptop.

Item Performance

The pictures in this review were taken without a flash, as the screen was nearly 100% unreadable with a flash. In a full flash setting, glare is not reduced. In the real world, in actual sunlight, the screen also appears to increase glare – for both you and the snooping onlooker. For the targeted viewing angles, the screen data was nearly 100% invisible, but with only a slight increase in glare for the legitimate user. As demonstrated in the photos, the glare is extremely apparent for a snooping onlooker. This helps with the privacy effect.

In normal light settings with an individual sitting directly next to the laptop with the Privacy Filter applied, an extremely large percentage of the screen is invisible to the onlooker adjacent to the user. The filter does an excellent job of concealing the screen data. However, do not expect the Privacy Filter to work with individuals directly behind you! This drawback is most likely to occur when sitting in an aisle seat on an airplane. It is still possible to view some degree of screen data in this situation.

As mentioned before, the notch in the top left portion of the screen is to facilitate easy removal of the privacy filter for when it is not required.

3M states screen data is not distorted when viewed beneath the Privacy Filter. This claim is true, to a point. Screen data is not “warped”, however the screen is noticeably darker. Most documents have a white background, in which case this is not too negative of a factor. However if watching a darker movie, expect a decrease in brightness. Even in direct sunlight, the screen is still usable but this likely varies based on the quality of your laptop’s backlight.

The decrease in brightness is quite noticeable, but as with everything else, the trade-off between security and usability is omnipresent, like an overseeing deity of sorts.


While not perfect, the 3M Privacy Filter does live up to the majority of its claims. Due to its easily removable nature, it is best used when entering a public area in which the privacy and security of your screen data is at the largest risk. When privacy is not required, the screen is easily removed and stored in the provided packaging.

The 3M Privacy Filter was purchased at a retailer with a fairly liberal return policy. It has been several months, and I have no intention of returning the product for performance reasons. For the money (roughly $50), the 3M Privacy Filter is worth the security of knowing your screen data is viewable to only those within a certain radius.


  • Significantly reduces ease of snooping
  • Price


  • Screen can still be seen directly behind user
  • Slightly reduces brightness
  • Introduces a small amount of glare
  • Somewhat flimsy

Screen size availability:

Notebooks, Netbooks and Desktop LCDs: 10″ through 20″

Bottom Line

At $50 the 3M Privacy Filter it’s still a no-brainer for those who require confidentiality of their screen data in public. The 3M Privacy Filter is the only product in this price range in this space that performs this effectively.

Purchase the 3M Privacy Filter at

This is posted at the blog of Jeff Yestrumskas

Allow me to present some background of the history of ANSI art and why it may be interesting. Back before we had Facebook, MySpace, Google; before the dot com boom and bust, before DSL and cable modems, even before Yahoo, before Internet access was readily available, there were still many diehard nerds communicating online with dial-up modems. Instead of calling NetZero, Netcom or Earthlink, we were connecting and communicating through hobbyist-run Bulletin Board Services (BBS). BBS’s existed as early as the 1970s, but gained popularity in the 1980s and peaked in the early 1990s.

A BBS is a text-based piece of software often run on a PC with one or more modems that allows users to dial-in and participate in message forums, play games and transfer software. Wow, it sure sounds like the Internet, but with text only. Most BBS’s operating solely with ASCII and ANSI character sets on DOS-based VGA (16 colors!) terminals, which meant scrolling, blocky text. This was not pixelated, this is what we had to work with. The words drab, boring, void of anything aesthetically pleasing may come to mind.. Not so fast. Aspiring and inspiring artists were able to transform this seemingly eternally bleak text-based environment into something magical. Using the 16 available colors, some amazing art was integrated into the BBS environments.

This art, known as ANSI art is something that grew solely out of necessity, something that could only have existed within the medium created by the personal computer boom of the late 1980s and early 1990s.

This art was viewed during the BBS experience in the homes. Many ANSI artists part of the BBS communities were of the same demographic and settings – teenagers addicted to computers at a very young age; myself included. The ANSI art scene grew rapidly and soon “groups” had formed, and released ANSI art packs under pseudonyms on a regular basis.

The ANSI art scene nearly faded into oblivion as the BBS era was almost in it’s grave due to the Internet explosion in the mid 1990s and beyond. To this day, ANSI art packs are still released, and great archives of these artifacts exist.

A friend of mine, Kevin Olson is holding an ANSI art show at 20 goto 10 gallery in San Francisco. Kevin will be featuring ANSI art by some of the most famous artists, Lordjazz and Somms. Kevin really went all-out with this show. He will be using terminals which scroll ANSI art to ensure the art is displayed as originally intended. This is going to be a great event, and I already know many folks who are traveling from all over the country to attend.

For now, to get your ANSI art fix in, take a look at some of the packs found on

For further reading on BBS’s and the culture, their history and a great archive of works produced take a look at Jason Scott’s Jason has also produced a wonderful BBS Documentary DVD set which documents the many niches and subcultures (hacking, phreaking, anarchy, virii, ANSI art) found in the BBS scene of the past.