Nothing, think of it as the same as if you just emailed your friend a phishing URL. Except this way is much more convenient to do so :) Pretty soon there will

Nothing, think of it as the same as if you just emailed your friend a phishing URL. Except this way is much more convenient to do so :) Pretty soon there will be a "block whoever sent me this" feature, but I haven't got around to building that yet. Until then, just don't add people on Tabd that you don't know and trust!