On 8/13/14 1:22 PM, Eric Hellman wrote:
> It seems that Code4Lib hasn't discussed this., though the news is 2 weeks old. It seems that there are libraries using social share tools from AddThis", a company that has been using a technology called "Canvas Fingerprinting" to track users. 
> 
> In other words, it looks like libraries are giving away the user-privacy store.
> 
> For example, AddThis is used by my public library's Polaris catalog (BCCLS).
> 
> I'd be interested to learn how widespread this is.

It's pretty widespread in general, but I don't know how many libraries
are using it, or why.

It's a concern regardless of absolute numbers, because it targets people
who are concerned about being tracked and have taken steps to make
cookies less effective. (For example, I discard cookies at the end of
each browser session, making long-term tracking ineffective.)

It isn't "virtually impossible to block"; mapping addthis.com on the
client computer to 127.0.0.1 (using /etc/hosts on Linux and Unix
machines) does a nice job of it. But anyone who uses it really is
betraying the user's trust.


-- 
Gary McGath, Professional Software Developer
http://www.garymcgath.com