That included businesses like Facebook which offered chat functions, or even Mr Dotcom's cloud storage business Mega which says it intends offering an encrypted email service soon.
"How are they going to define telecommunications providers as part of this review given the landscape has changed dramatically and there are a lot of other companies now providing these services that weren't in existence 10 years ago?", the source said.
Ms Adams yesterday said the definition of network operators was already provided for in the act and "we're not proposing to change that".
However, she said the Government "will look at some flexibility to allow us to amend that as future situations dictate".
Mega chief executive Vikram Kumar said encrypted communications were now common across a number of services such as Skype or on social networking sites and were a tough issue for regulators to deal with.
"I don't doubt that there will be some people scratching their heads on how do we update the act to intercept encrypted communications."
Mr Kumar said he was aware that some telcos were questioning why "over the top" services, such as Facebook or Skype weren't subject to interception but long-distance calls were.
Mr Kumar was appointed chief executive of Mr Dotcom's cloud storage business Mega shortly after it was launched earlier this year. Mr Dotcom's previous business Megaupload was shut down after police raided his Coatesville mansion, an operation that was preceded by what turned out to be illegal surveillance of him by the GCSB.