I mean… they did try to kill me. I was just wondering if this effects the game as a whole. Is there any effects if I do or do not warn them?

Sadly, like many other such "choices," it' s completely immaterial.

Try it and you'll see what I mean. Save the game beforehand if you're still worried.

it changes the start of 3 a bit (sorta) so are you a Renegade? then f'em they did try to kill you after all...
or.. are you Paragon and try to do good deeds then yes, warn them. unfortunately the outcome is the same, sorry if i spoiled something.

Nah, I did not warn them, renegade here, but I'd still let them get ♥♥♥♥ if my shep was Paragon.

Originally posted by ironichypocrisy:

it changes the start of 3 a bit (sorta) so are you a Renegade? then f'em they did try to kill you after all...
or.. are you Paragon and try to do good deeds then yes, warn them. unfortunately the outcome is the same, sorry if i spoiled something.

In ME1 I went full paragon but in ME2 I am aiming to be half renegade and half paragon. The main reason I don’t want to warn them is because since I’m playing insanity mode, playing as the Sentinel, and I died a whole lot of times, more then any other mission, this was essentially payback for all the time I wasted on this mission. So yeah, I did go renegade in the end.

Originally posted by ironichypocrisy:

it changes the start of 3 a bit (sorta) so are you a Renegade? then f'em they did try to kill you after all...

Exactly, the whole damn colony wanted me dead and there a bunch of cultists worshipping a damn tentacle monster. Why warn them in the first place? Just for them to escape and spread their harmful ideology? I’ve never hated a race in a rpg game but Batarians has to be the first.

Originally posted by Arbiter Spectre:

In ME1 I went full paragon but in ME2 I am aiming to be half renegade and half paragon.

A little off-topic but I should warn you that in ME2 that is a sub-optimal strategy. 'Nuff said, I won't unpack my statement because spoilers.

I did, because even if individual Batarians tried to kill me, the whole colony isn't responsible. By that logic I should destroy human, Asari, and Turian colonies too.

there are quite a number of Asari trying kill you in 2... maybe they have it coming... ;p

I find the best Shepard is Paragon actions, but Renegade answers a lot of times when it comes to making the most likeable without him/her either being a stuck up morality preacher or complete asshat.
A lot of minor renegade answers actually makes him/her feel more understandable to the common people.