Commissioner Stephen Sedgwick told a Senate estimates committee on Tuesday he hoped careers were not ruined while the service built its experience with Twitter, Facebook and blogging by public servants.

Mr Sedgwick also said the service's response to a Taxation Office official's inappropriate tweet about an anti-pornography campaigner had not been good enough.

The commissioner told the finance and public administrative legislative committee that it was younger members of the service who were more vulnerable to making big mistakes online.

He said the bureaucracy was making efforts to ensure that its young members were aware of their obligations under the public service code of conduct.

''This an evolving area, we try to make clear to public servants, especially young public servants who are kind of used to living in a fish bowl and think nothing of putting stuff on their blog, their Facebook page or their Twitter account that I'd never write in a million years,'' Mr Sedgwick told the committee.

''We keep trying to say to people that you have an obligation to treat people with courtesy and respect.

''You have an obligation to be able to convince your customers, whoever that might be, your colleagues, your minister, the alternative government, that you are ethical, politically impartial and you can serve the agenda of the government of the day.

''You don't express yourself in ways that are so extreme that it would call that into question and you certainly don't tell your clients what you really think of them when you go home onto the blog at night.''

But the commissioner said he was resigned to a slow and painful learning process.

''This technology is moving and case law and experience will build painfully, I suspect,'' he said.

''We just hope that careers aren't ruined in the course of it.''

He had earlier told the committee he expected individual agencies to be the first port of call when online misconduct allegations were made.

''They don't have to instigate a formal code of conduct, there's lots of ways of skinning a rabbit, if you like, but I would expect them to deal with it,'' Mr Sedgwick said.

''If the complainant was dissatisfied, they could come to us.''

He also conceded improvements were needed in procedures for dealing with complaints about online activity in the wake of a row between anti-porn activist Melinda Tankard Reist and the ATO over a tweet sent by one of its officers.

Senior ATO officers apologised to Ms Reist, who was described as ''rootable in that religious feminist way'' by public servant Darryl Adams on his fake Paul Keating Twitter account.

Ms Tankard Reist was angry she was not told of the outcome of her complaint, with the department citing concerns for Mr Adams' privacy and the commissioner told the committee on Tuesday the guidelines for agencies dealing with such cases would be changed.

''We will look at that guidance again and see if we can be a bit clearer about how to deal with these issues,'' Mr Sedgwick said. ''Revisions won't be made in the next five minutes … but they will.''