What were they thinking? Kendall and Kylie Jenner have "deeply apologized" after introducing a new line of T-shirts that feature the Keeping Up With the Kardashians stars' faces plastered over iconic rock 'n' roll images, including ones of Ozzy Osbourne and Metallica, among others.

The shirts, released under the Kendall + Kylie apparel line, retailed for $125 each, but were quickly removed from the retail website after criticism from the various music stars' camps, who accused the sisters of illegally and distastefully using the images.

Sharon Osbourne called out the Jenner sisters in a Tweet, stating, "Girls, you haven’t earned the right to put your face with musical icons. Stick to what you know…lip gloss."

Meanwhile, in an Instagram post, late rapper Notorious B.I.G.'s mother Voletta Wallace stated, "I am not sure who told @kyliejenner and @kendalljenner that they had the right to do this.  The disrespect of these girls to not even reach out to me or anyone connected to the estate baffles me.  I have no idea why they feel they can exploit the deaths of 2pac and my Son Christopher to sell a T-shirt. This is disrespectful, disgusting, and exploitation at its worst!!!"

Following the online backlash, Kylie apologized, stating, "These designs were not well thought out and we deeply apologize to anyone that has been upset and/or offended, especially to the families of the artists. We are huge fans of their music and it was not our intention to disrespect these cultural icons in any way. The tee shirts have been pulled from retail and all images have been removed. We will use this as an opportunity to learn from these mistakes and again, we are very sorry."

Led Zeppelin, The Doors and Pink Floyd were among the other bands featured in the ill-conceived T-shirt line. The Metallica T-shirt, featuring a sultry image of Kylie superimposed over the Kill 'Em All album cover, can be seen in the tweet below:

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