So far I've had a pretty miserable time with playing Hot Pursuit online. Regardless of whether I'm playing as a Racer, or a Cop, I seem to get taken out almost exclusively by my supposed "team mates." When I'm playing as a Cop, as soon as the race starts I usually have at least one player on my team that immediately starts slamming into me at the beginning of the race, and then as soon as their equipment is available, they start dropping it on their fellow Cops. Same thing goes when I'm a racer. I've had multiple Hot Pursuit games where I've gotten taken out completely by one of my own teammates. No one on the opposing team ever touched me, it was all my own team members equipment, or them slamming me into oncoming traffic, causing me to wreck.
I've had a couple occasions where I know for a fact it was on purpose, because the guy was laughing at us over voice-chat, and outright said he was doing it on purpose. Saying crap like he's "role-playing a dirty Cop," and is going to help his "felons friends get away." The other times may have just been accidental. Bad players just playing bad. Either way, it pretty much completely ruins the online experience. At least for me it does.
 
This is the equivalent of friendly-fire in FPS games. When it's on, it almost always gets abused. It's usually only a matter of time, and then the game is ruined for other players. It's no different for this game. I've gotten to where I only do the Interceptor game type. Since it's just me against someone else, and I don't have any team members ruining things for me, purposefully griefing, or otherwise effing me up in some way... I really wish they had a Normal, and Hardcore mode in this game similar to how FPS games do it. Hardcore for people that like friendly-fire, and Normal for those that don't.
 
Anyways, it's a shame because the concept of this game, Cops vs. Felons, has the potential to be so much fun. I just haven't been able to experience it yet. It's been me vs. 7 other racers, and that's it.

When you're a racer you are not a teammate. It is every man for himself. I always get in front and then start dropping spike strips in road blocks. If you get ahead of the pack then most of the cops will get bogged down trying to take out all the guys bunched up behind you. So taking out other racers is completely acceptable.  
 
But as for cops taking out other cops, that makes absolutely no sense at all. The guys doing that are idiots, they are not getting any points for that.

" When you're a racer you are not a teammate. It is every man for himself. "

Welcome to online gaming. If you don't have actual friends to play with just be sociable with people you find in random games that aren't trying to fuck you over. All online gaming is better when you're playing with people you know. Even if it's only people you know from the game.

that game sounds sweet !  i should try it out.. hm.

My online experience was quite pleasant to be honest, although this was a few weeks ago just before I S-Ranked NFS. That would probably mainly be down to the fact that as a racer I'd just slipstream my team mates, take the lead and never look back. As a cop I occasionally got caught be a stray EMP from one of my team mates but nothing like you're describing.