Gmail, the planned free e-mail service from Google, could be facing strong legal opposition in California
Gmail is facing opposition from more than one direction
A draft law is being drawn up by local Democratic Senator Liz Figueroa, who calls Gmail "an invasion of privacy".
Google is being asked to rethink the product, which plans to offer 100 times the storage offered by some rivals.
The problem, Ms Figueroa says, is Google's plan to make revenue from users agreeing to their incoming e-mail being scanned for targeted advertising.
Californian Senator Figueroa describes the service as being a bit like "having a massive billboard in the middle of your home".
The targeted adverts would use key words after scanning your private e-mail - posting adverts for pharmaceutical products, for example, if a message mentions a medical condition.
Google's plans have already come under fire from privacy campaigners objecting to adverts linked to the content of messages, and to the permanent storage of email.
UK-based campaign group Privacy International has complained to the UK's Information Commissioner about Google's plans to send users links to advertising based on a computer scan of their correspondence, and presumed interests.
It also pointed out that Google's terms of service did not allow users to delete their emails permanently, despite European data protection legislation which gives users full control over their own communications.
At present, users of Google's internet search engine receive advertisements for commercial sites linked to their search topic arranged down the right-hand side of their screens.
Gmail would use similar technology to scan emails and offer advertisements.
Other websites - including rivals such as Yahoo - use similar methods to select which banner adverts appear on top of a search page.
Google said in a statement that it intends to work with data protection authorities across Europe to ensure concerns are resolved.
It says the content of users' email would remain private because the process would be fully automated.
The internet search engine company has promoted free storage for each user of the equivalent of 500,000 pages of email among Gmail's benefits.
Google says this will enable users to retrieve vast amounts of old emails, and that it will back this up with superior spam filtering.
Google is privately-owned, but expected to float on the stock market later this year, a deal that could value Google at up to $25bn (£14.7bn) - slightly more than listed online retailer Amazon.
The California-based company was founded in 1998 by Larry Page and Sergey Brin.
I don't think your privacy can be invaded if you know what the service is doing before you sign up. It's a free service and nobody forces you to use it and have your e-mails screened.
David Cox, Southampton, UK
This is no different to Google's search engine giving you advertisements based on what you search for. As long as information on which adverts have been picked for you is not stored, and the process remains entirely automated, I wouldn't have any problem with using a service like this.
Alex Oughton, London, UK
If anyone has a problem with the service offered they can choose not to use it. This seems to be 'nannying' of individuals. If the user base does not want this sort of targeted advertising in exchange for free storage, the product will die a death. If it proves popular regardless of or potentially because of the advertising - what's the problem?
Andrew Foster, UK
People should get a grip. Our personal "privacy" is already invaded at a far more intrusive level by tele-sales, direct marketing and most worryingly by government. If a company offers a product in exchange for an advertisment platform as long as the rules are made clear where is the problem?
David Price, USA
Yes it's an invasion of privacy but you have the choice to use GMail or not - in other words, you have the choice to have your privacy invaded or not. So I think it's a good idea but it's not a service I'll be using.
Robert Stephenson, Altrincham, England
Anything that scans emails for content / key words is an invasion of privacy. It would be like the Royal Mail opening letters and placing adverts inside the envelope
Of course it is an invasion of privacy - just imagine somebody asking you to give them the right to read all your letters, keep a copy of each and flood you with advertising leaflets based on what they think you might buy! Nobody would ever say yes to such an "offer".
But then there is a simple way around this: just don't use Google's Gmail; nobody is forcing you to use it, so just don't. If everybody were just to ignore them, Gmail would soon disappear again.
George, Cambridge, UK
Yes. It is the equivalent of having someone open your post and putting some junkmail inside. I don't think I will be using it!
Nick, Madrid, Spain
Gmail sounds excellent and I have no problem with targeted ads. The Gmail advertising method will be much less intrusive than the ads found on Yahoo or Hotmail. People should read the terms and conditions and if they are not happy with what they must agree to to use the service, then don't use it.
No doubt in my mind that Google has already shown itself to be a leader in snooping. They already make public EVERY post you make on newsgroups/discussion groups. They may be big and powerful but I will never use their email system and if any of my friends do, I will notify them that I will not reply or write to a Google email system.
Robert, St Louis MO USA
Assuming the ads would be displayed in a similar way to that employed on the search engine (i.e. that they would not send me spam, merely add ads into my regular email) I would be happy to sign up to such a service. For once, the adverts being displayed may actually be something I am interested in, and it would be a much better way of targeted advertising. I realise very little is truly "free", and the only way they can offer such an immense amount of storage is by charging more for the ads, as they can assure advertisers that the ads are targeted well. As for the storage, anyone who uses a free online email system should expect it not to be perfectly private, and if Google really want to keep copies of my jokes, forwards, daft comments, innuendos, and indeed the spam I receive, good luck to them! I have no problems with the service at all, provided the T&Cs are clear when the user signs up.
Philip Holbourn, Coventry, West Mids, UK
This has nothing to do with invasion of privacy and stinks of politics. A bit like "having a massive billboard in the middle of your home"? Has the good senator not noticed the number of homes with TV sets showing 24/7 adverts with occasional short 'programme' breaks?
Dave P, Frome, UK
No more than it is already invaded by the authorities. It is a bit rich for a legislator from the USA to attempt to block Gmail on the grounds of invasion of privacy when we all know that the US government has a facility monitoring and reading all and any e-mails it pleases. Ditto GCHQ in the UK.
Mike Edwards, Blackpool UK
Junk mail drops through letterboxes, TV programmes interupt every 15 minutes, billboards everywhere. Most is poorly targeted. Google does target scientifically and as e-marketing begins to dominate over TV and paper this will eventually save many trees and us all many wasted hours. Importantly, research show us that people accept targeted ads. As for privacy, this probably is a technical and privacy issue. Forcing it should bring clarity and a legal framework. Google will never be the sole email provider, but good on them, we hope to be @gmail one day.
iMakeWebSites Ltd, Manchester Lancs
I don't have such a high opinion of myself to think that anyone would want to read my email, and even if they did I wouldn't care. Due to the way email works, it is far from private anyway. If I have anything to send that I want kept private I use PGP. My only concern is that with the amount of junk mail advertising certain body enlargements, the GMail system might think that's what I am into, and then display even more adverts for it!
Marc, Reading, UK
Google shouldn't be allowed to scan e-mails for any purpose. It's like Royal Mail opening everyone's mail, personal and business, reading the mail, making a note of any 'key words' and then resealing the mail including any applicable adverts. This is quite clearly not only an invasion of privacy but to my mind it would amount to opening up the channels for any kind of 'snooping' of mails. How can we as a culture expect to move forward by depending upon technology if we cannot be assured of its security, even at the most basic of levels? If G-mail was to go ahead then the user should be given an 'extremely' clear choice of whether their mail can be scanned for these alleged 'key words' and the implications of such scanning. Additionally once the mail has been 'downloaded' from the G-mail server then the stored server mail should be deleted.
Jason , Basingstoke, England