Say for instance i was searched by a police officer in the street for no reason and i complied and they found this, could they confiscate it even though i wasn't using it? is it classed as an offensive weapon?
Depending on the specifics of the situation, yes they could. No way to know know if they actually would though.
I have been frisked by a cop last year on halloween, they were searching everyone coming out of the bar. He looked at my laser, I told him what it was, and what not to do with it. Also told him that it is not illegal (which in the US is true, possession of laser is legal). It helped a great deal that the laser had a key safety, and when he clicked the button, absolutely nothing happened.
He did take a small 2" keychain knife, I had on my keychain... it was also legal, but frankly it wasn't worth the argument over something that's $5.
We talked for a bit, and went out separate ways. Actually gave me his business/police card, said he wanted to know more about lasers. One of the nicer cops I've ever dealt with.
This is a HUGE reason I'm a big fan of the lasers offered by skylasers/laserbtb.
I also wouldn't bother asking a beat cop about legalities. Cops are taught/told, if it looks dangerous take it, let the courts figure it out.
If you keep the laser and the battery separate, your chances of getting in trouble would also be significantly reduced. Also helps if the laser looks relatively innocent, as opposed to say having an assault crown.