satoshi or anyone with the alert key for that matter, cant put your client into 'safe mode' any longer, the worst thing they could do is push a message to your client.

'Until version 0.3.20, Bitcoin went into safe mode when a valid alert was received. In safe mode, all RPC commands that send BTC or get info about received BTC return an error. Current Bitcoin versions no longer go into safe mode in response to alerts, though Bitcoin will still go into safe mode when it detects on its own that something is seriously wrong with the network.' - https://en.bitcoin.it/wiki/Alerts

'The known private key holders are Satoshi Nakamoto, Gavin Andresen and theymos. There are other people able to issue alerts in the event of the incapacitation of the aforementioned.' - I would imagine sipa, waldimir, Corallo and a few others can do alerts also.