Is it illegal to save someones picture from facebook?

[Wifi]

Okay so i do graphics and i sometimes use some girls pictures from facebook without permission to edit and use, i don't ask them because they'll find it a little creepy, i live in the UK, is it illegal? I have about 15 pictures of girls saved on my computer, shall i delete them? I'm unsure if what i'm doing is illegal, thank you.
I've already said, to make stuff on photoshop.

[Mr. Sonny]

Should be no problem.

[fagashlil]

yes they are not your pictures your suppose to ask for permission , your a thief , what did you thieve 15 pictures for ?

can we see what you make and we will tel you whether its good or bad

[Rosie]

Its illegal proably but you proably wont get in trouble. But Its a good idea to delete them from your profile to be safe.

[tushar kohli]

LOL..NO! Donchu worry donchu worry child,these hoes aint got nothin on you.


(SHM song reference)

[Ben]

It's a copyright violation, which is a civil issue, not a criminal one. So it's illegal, but the police aren't going to arrest you for it.

[?]

No, once it's on the website its public. There should be no problem, those who said its illegal, they know nothing about internet rule. So please don't comment. You can save it as long you not reproduce or sell it you are fine.