The issue of whether it's legal to rip personally owned DVD movies is mired in more shades of grey than the novel.
Handbrake, an open source media conversion utility, apparently does not violate the DMCA as it's not able to circumvent CSS copy protection by default. The end user needs to manually install a separate .dll file to do so.
However, DVD Catalyst is apparently based on the open source Mencoder/MPlayer which utilizes the libdvdcss.dll library to decrypt DVDs allowing it to be ripped. It also appears that the open source libdvdcss.dll, which uses a list of player keys or brute force methods for authentication, has not been legally challenged, as it's commonly used in free media players. This in contrast to conversion utilities that use DeCSS, which uses a cracked player key, and technically illegal to manufacture or distribute.
However, may be a moot point as the DMCA considers it illegal to circumvent copy protection for purposes of copying content except for a few exempted purposes.
Adding to the confusion, the U.S. Copyright Office refused to exempt space shifting, converting copyrighted digital content to a different format, effectively making it illegal.
Some AV software, such as Bitdefender, auto blocks the current version of DVD Catalyst from running, without it being manually unblocked.