There is no such thing as too much security when it comes to mobile devices. There are ways around pretty much every security method out there—from using fingerprints to figure out pattern locks to programmers creating malware that doesn’t fit into anti-virus definitions.
With that said, how many people knew that SMS and MMS messages were stored in logs and could be viewed, even after they’re deleted, by anyone who picks up their phone? It’d be safe to bet not many. And while it’s not a security risk per-say, it’s definitely a chance to invade privacy even when one thought their privacy was being protected. This is a problem that XDA Forum Member jeboo is looking to solve for at least owners of the AT&T Samsung Galaxy S II.
What the modification does exactly is edit the mms.apk to skip the portion of code that puts the MMS or SMS into the log and since they stop being put into the log, people can stop using that method to read your old SMS and MMS messages. In the words of the developer:
Note that with this patch the log entries are never saved. So if someone gets a hold of your phone and tries to dig them up, you’re fine!
The application of the patch requires some apk compiling and de-compiling skills. So if you’re not quite brushed up, it’s recommended that you do so before attempting. And, as usual, don’t forget to make a backup before changing anything, just in case.
For additional information, the full instructions and discussion, check out the original thread and get those text messages gone for good._________