Yes, it actually took 3 days for someone to create a script that read the DAG (not a blockchain) and "catch" users' transactions of amounts similar to that used to pay the attestation fee. Initially, only a single script was active, but after 2 more days, we saw 5 or 6 more. Today, we decided to end it and remove the fee entirely, reverting to a basic referral link. The scripts caused others to develop ways to "milk" the scripts by generating transactions resembling that of users normal behavior from different addresses. (The headless light wallet allows for that) It was quite interesting to see, really :)