There are things they could do
The most obvious ways Sony could rein things in a bit would be:
* Add a challenge / response during PSN sign on. e.g. asks firmware to checksum some arbitrary range of bytes in its fw or memory to proceed. Wrong answer gets flagged.
* Embed silent audits into fw updates and into games. There could be multiple audits so it's not a simple case of patching a few lines of assembly. E.g. an audit might be done in obscure corners of the XMB, e.g. change wallpaper and an audit fires off. Audit would search for popular homebrew / pirate apps such as iso loaders. Results of audits get sent up to PSN or Sony via any active network connection.
* Start padding out game data with garbage, duplicate data, etc so games fill a 25Gb, 50Gb or 66Gb disc. (Sony has a format in the works for 66Gb)
* Banning anyone stupid enough to fail an audit or run cracks and sign into PSN.
* Move more content online so PSN becomes more necessary
At the end of the day none of these things are foolproof. The intent is to detect piracy and slow down / discourage it. Even that is worthwhile if it puts days or weeks between games being cracked, if ever.
On the flip side they could also foster goodwill by:
* Recognize things have gone way beyond the OtherOS removal so reinstate it. Split the pirates and homebrewers into 2 camps
* Step up firmware updates again with new functions. Keep crackers on the backfoot by providing reasons for users to stay legit.