Report him. UPDATE

This user named DarkMind78   (also known as Socket78 CelestiaStellaBailey and EvilHonor1962  and Fastnonsense ). has HARRASED and SEXUALLY harassed my friend MagiTheSquishyDrawer (also known as MagicRoseTheHedgi) he has also harassed me. Here's evidence of his harassment.
Screenshot 2016-10-18-19-57-19
Screenshot 2016-10-18-19-50-51
Screenshot 2016-10-18-19-50-39
Screenshot 2016-10-18-19-50-34
Screenshot 2016-10-15-19-22-44
Screenshot 2016-10-15-19-22-11
Screenshot 2016-10-15-19-22-18
Screenshot 2016-10-15-19-22-24
Screenshot 2016-10-15-19-22-38
Here's evidence of my friend MagictheDrawer.
And here is my evidence of his spamming.
Found more evidence of him stealing!!Screenshot 2016-10-18-21-10-40
Stalking my profile (the other screen shots of those were lost so this is the only one that I found)QScreenshot 2016-10-18-22-30-41
Well look who is stealing again? I can keep this up all day. 
Screenshot 2016-10-21-07-36-19
Screenshot 2016-10-21-07-36-29
Screenshot 2016-10-21-15-23-23
Well look who stalked my profile once again
Screenshot 2016-10-21-07-53-04
His "Apology" to me and everyone else
More evidence, thanks to rwbyy for allowing me to use their evidence. 
 And
 Screenshot 2016 10 21 18 33 13 By Hustles-dalvcsu
Screenshot 2016 10 21 18 33 08 By Hustles-dalvcs8
Screenshot 2016 10 21 18 33 03 By Hustles-dalvcrs
Faking his "I'm sorry act" by deleting the art and leaving one up. Screenshot 2016-10-21-18-52-07
"I'm sorry act" 2 Screenshot 2016-10-21-20-35-26 by deleting everything in his gallery to act innocent. Uhm last time I checked you ain't innocent 
Stealing art again; 
Screenshot 2016-10-22-00-37-04
Screenshot 2016-10-22-08-21-16
Screenshot 2016-10-22-08-21-12
Screenshot 2016-10-22-08-21-06
Screenshot 2016-10-22-08-20-51
Screenshot 2016-10-22-08-20-41
Awe, thanks for visiting. If you haven't noticed, I can keep this up, DarkMind78 stalking my profile again. Sad life.
Screenshot 2016-10-22-11-18-01
Playing innocent slowly by deleting the art he stole
Screenshot 2016-10-22-14-20-43
Wow I'm so happy hint the sarcasm in my voice? 
He will block me again shortly, but still, how pathetic? Screenshot 2016-10-22-14-42-01
Video~~~ 
His faking innocence again Screenshot 2016-10-22-20-10-21
Stealing agsin Screenshot 2016-10-23-03-30-45
He made a new account, here it is: fastnonsense.deviantart.com/
The art he stole: Screenshot 2016-10-23-10-38-50
New stolen art; Screenshot 2016-10-24-09-04-51 he wants a new video of him. But I'll do that when school is over. 
Stalking my profile (Socket78) Screenshot 2016-10-24-19-04-19
Stealing art on his darkmind78 account: Screenshot 2016-10-25-09-17-35
Stalking my profile (CelestiaStellaBailey) Screenshot 2016-10-25-09-19-20
I'm done updating, go here <da:thumb id="666525033"/>