https://www.overclock3d.net/news/software/2k_stops_disk-to-steam_borderlands_conversions_1_day_before_game_of_the_year_upgrade_announcement/1
 
Disk-based games are safe, right? Surely they are not at risk of server shutdowns, rendering them unplayable or otherwise hampering my ability to play my legitimately purchased copy? Well, no. Borderlands disk-based version and its use of SecuROM has made physical editions of the game playable. Before now, owners of the disk-based version of Borderlands were able to convert their disk-based version of the game to a Steam-based copy, granting access to the game using the Steam client. Problem solved, I can turn my old disk-based copy of Borderlands into a Steam version, right? Wrong! Two days ago, on March 27th, 2K Games removed their "Borderlands Granting Tool" from Steam, preventing legitimate owners of Borderlands from converting their unplayable physical copies into playable Steam versions. If you didn't redeem your Steam copy of Borderlands on Steam before March 27th, you are stuck with your unplayable disk version.

Okay there needs to be a lawsuit here, this is deeply unethical and criminal!