Tricks to throw off bots harvesting emails

Spam­blog­ging on using CSS Pen­cils as a way to avoid get­ting your email address har­vested: Proof of con­cept to throw off the bots.

Var­i­ous scripts already exist that can gen­er­ate non-harvestable mailto-links, but the dynamic bit is nice. How­ever, it appears to be a bit com­pli­cated, so I’m think­ing that maybe Shaun Inman’s IFR can be put to even bet­ter use?

In short, it’s a flash alter­na­tive to the well-known Fahrner Image Replace­ment (FIR), using CSS to replace var­i­ous bits with graph­ics while pre­serv­ing decent markup. Down­side: You need to gen­er­ate a lot of images, most of them prob­a­bly just dif­fer­ent words using the same non-websafe font. IFR to the res­cue; one sin­gle flash file and a bit of javascript to do the replace­ment. I’m think­ing of play­ing with it in the upcom­ing blog redesign. But couldn’t you do a mailto-flash piece? I’m not really sure how bots inter­act with flash, but hope­fully they’ll give up…

Of course, you’d have to twist the seman­tic bit, but that’s part of the point…