Can I damage another person AdSense account? (without intention)

i dont quite get what you mean?

If I recall correctly, you can get in trouble if you have more than one adsense account's ads showing on a single page, which it sounds like you might be. Besides that, I've never personally seen any other issues.

My 2 cents.

You can damage it if you go and keep click on their ads on the their site. Especially if they are a small time operator.

I'm curious:
I think I understand your question.
The site is Forums and Classifieds
Member 'A' (Any Member) can use their AdSense Link on their OWN profile page, but nowhere else
ANYBODY can post publicly in Forum/Classifieds; what I'm trying to be clear on:

Does your site actually PERMIT this illegal material to be posted?
Or is it just 'possible' that it gets posted sometimes, and you try to remove it?

There is nothing wrong with a site having multiple member's adsense ID's across the site, so long as no more than 1 ID is used per single page. (for an example, infobarrel.com does this which supports revenue sharing with their members (side note: it's done in a pretty fair way, as well).

So, there is nothing that can get your member's banned, Unless your site is just completely filled with illegal content. If you don't actually permit illegal content, and try to clean it out before it gets indexed by the search engine, you should actually be fine. You just have to make sure that ONLY 1 adsense ID is EVER used on any single page at a time.

I would suggest you place a warning on the site that their Adsense account could be banned. Who knows what Google thinks and I guess it depends on the level of illegality being posted. Even if they wouldn't ban it today, doesn't mean they wouldn't tomorrow.

Protect yourself by telling them it could be banned otherwise you're going to get a lot of angry members if they do.

Personally, I wouldn't risk Google associating anything I do with something illegal. But that's up to you... Definitely warn your clients, however!

Multiple accounts on one site is fine, on one page is also fine up to the limits of ad units per page imposed by the terms of service.

Adsense should not be on a PAGE that violates the terms of service. As long as the PAGE not the site in general complies then the adsense account on that page should also be fine.

Personally I wouldn't put my adsense account on any page or site that I didn't have full control over, I value it too much.

Thank you! I will do it!

I not do something illegal, just on the internet wander different stories, so I want to my members ads are safe.

I also wouldn't put, but how many people so desires

The thing to do here if you're not sure is to put up a warning of some sort (even if it's just in the terms of service) that you take no responsibility for anything that happens to their adsense account as a result of something posted in the forum. Seems like it should be easy enough to write in a liability waiver of some sort.

Once that's in place, then you can spend time reading through Google's own Terms of Service to determine whether you think there is any possibility of banning. However, having that waiver in place is probably a good idea either way.

@rudulah

the question was not about what will be if google banned me... but thanks.