Don's Home Technology Web Development Privacy Contact

Under Construction.
  • Don't list personal information, name, email, phone number, address without a person's permission.
  • If you do list name or phone number take efforts to hide it from web crawlers. See below.
  • Do not list birth dates for living family members on web sites even if they give you permission to list their names.
  • Do not list information on family tree (genealogy) web sites which would allow a living person's Mother's maiden name to be identified.
  • If you collect information about visitors to your web site you must have a privacy policy statement on how that information is used.

Email and Phone Number hiding:
Silvan Mühlemann put up a web page with nine different email addresses coded in ways other than plain text so they would look normal when displayed in a browser but would be more difficult for web crawlers (spambots") to identify as email addresses.
Over a 1 1/2 years he counted how much span he received for each address. The plain text version (No obfuscate) received 1800 spam mails (3.3 emails/day) for a total of 21 MB.
See: Nine ways to obfuscate e-mail addresses compared
Method 1 and 2 generated no spam. But now that they are published will that be true? E.g.
1. Display code right to left (rtl)
<style type="text/css">
span.codedirection { unicode-bidi:bidi-override; direction: rtl; }
<span class="codedirection">moc.etalllit@7raboofnavlis</span>


2. Put a null character which doesn't display in the middle:
<style type="text/css">
p span.displaynone { display:none; }

silvanfoobar8@<span class="displaynone">null</span>

5. using javascript generated 144 KB of spam.
<script language="JavaScript" type="text/javascript">
var string1 = "silvanfoobar6";
var string2 = "@";
var string3 = "";
var string4 = string1 + string2 + string3;
document.write("<a href=" + "mail" + "to:" + string1 +
string2 + string3 + ">" + string4 + "</a>");

6. replacing @ and . with entities generated 1.6 MB of spam.

Note: 1 and 2 don't allow click to send email.

Privacy Policies:
The Platform for Privacy Preferences Project (P3P) specification at enables Web sites to express their privacy practices in a standard format that can be retrieved automatically and interpreted easily by user agents (e.g. browsers - Firefox, Internet Explorer, Safari). It specifies personal information that is gathered and how it is used, so browsers can pop up warning dialogs based on user preferences.

The White House Privacy policy for information collected on people who affirmatively request to receive e-mail or other services. Return to Technology

last updated 1 Mar 2009