[bschlinker]

"Facebook is indeed intercepting messages -- the e-mail is clearly passing through Facebook's servers, but this seems to be where it stays, as neither sender nor receiver are getting a copy."

Is this really appropriate use of the word "intercepting"? Typically intercepting carries a negative meaning -- like "the FBI is intercepting my postal mail and opening it before it reaches me". However, with their use of the word, every email I send is "intercepted" by multiple servers before it reaches its destination....

[j_s]

Facebook is intercepting messages by replacing the destination address (which email clients often do not readily display [opting instead for full names, even photos, etc.]), and now claims to have done so inadvertently. Multiple servers relay messages before they reach their intended destination, yes, but that is by design.

To continue stretching your analogy, I could claim that the post office x-ray/bomb scanners are 'intercepting' mail sent to me when in fact it is an understood part of the process to anyone who cares enough to research how things work. Someone moving my mailbox [edit: filling out a 'change of address'] and photocopying everything sent there is pretty clearly a reasonable use of the word 'intercepting'.