While the move addresses user privacy regulations and is a means of taking on rivals who use improved privacy as a selling point, critics also fear Alphabet's moves will benefit itself the most, meaning advertising spending will become even more concentrated on Google, thus harming consumers. Some of the sandbox proposals are particularly divisive, including first-party sets – which allow multiple domains to declare themselves to be one domain for so they can exchange data amongst themselves and still say it's been kept "private"- one such set, for example, could be youtube.com, google.com, and google.co.uk. The W3C Technical Architecture Group has declared the proposal to be "harmful to the web in its current form."