Last Friday we wrote about the Cookie’s cousin, Web Bugs. Insidious little creatures that invade your PC and let the marketing folks know exactly where you are. They even “talk” to their cousin cookies.
A most common usage of Web Bugs is through the use of emails. Web Bugs do 2 things when you open your email:
1. They tell the sender of the email that you read the message.
2. That your email address is valid (because you opened the email) and
3. That their email got past your filters
Spammers love Web bugs. They let the spammers know that the email address they harvested is real if you’ve opened an email from a spammer; allowed HTML in that email and allowed images to be shown in the email.
“Using Web Bugs, Spammers can prune their lists down to the small fraction of people reading their email and target those people with many more spam messages of different kinds. I.e. if you read a Spam message and are identified as a ‘good recipient’ by a Web Bug, then your email address just became a spam magnet! This is bad for you but good for the Spammers — as a larger percentage of messages that they send make it to viable recipients.” Protecting Yourself from Email Web Bugs
It is very difficult to filter web bugs. A good way to protect yourself is to use server-side email filtering. It must be a filtering system that auto-detects and removes Web Bugs in email messages. It must also leave the rest of the images in the messages intact.
If you do not allow “images” to be displayed in your email, this will also eliminate the power of Web Bugs. Don’t turn those images on.
The safest way to receive email, and avoid Web Bugs, is to receive them in plain text format.