Marcus is spot-on, as usual:
#3) Penetrate and Patch
There's an old saying, "You cannot make a silk purse out of a sow's ear." It's pretty much true, unless you wind up using so much silk to patch the sow's ear that eventually the sow's ear is completely replaced with silk. Unfortunately, when buggy software is fixed it is almost always fixed through the addition of new code, rather than the removal of old bits of sow's ear.
"Penetrate and Patch" is a dumb idea best expressed in the BASIC programming language:
10 GOSUB LOOK_FOR_HOLES
20 IF HOLE_FOUND = FALSE THEN GOTO 50
30 GOSUB FIX_HOLE
40 GOTO 10
50 GOSUB CONGRATULATE_SELF
60 GOSUB GET_HACKED_EVENTUALLY_ANYWAY
70 GOTO 10
