The clause that deals with updates of most website terms and conditions in the UK reads as follows:
Update Website Terms and Conditions
We reserve the right to update or otherwise change these Terms and Conditions without notice. if we do so we shall post such notice on the website. Your continued use of the website after notice of such changes has been posted on the website shall mean your acceptance of the Updated Website Terms and Conditions.
It is arguable that such website terms and conditions update clauses are legally ineffective as a way of providing updates to your website terms and conditions. Website terms and conditions are a contract. It is arguable that in order for any updates to that contract to be effectively incorporated they must (i) state that they are incorporated into the existing Website Terms and Conditions, and are subject to them; and (ii) they must be signed by the party affected (in the case of a website: the party affected must click an accept button or provide an electronic signature or reply to an email).
The UK case of Hollingworth v Southern Ferries Ltd  2 Lloyd’s Report 70 supports the point.
Hollingworth was a case about negligence and contracts. The case concerned the validity of an exclusion clause. The facts were that B, a friend of P, wished to book passage to Lisbon on D’s vessel for himself and P. B was given the ship-owner’s brochure by a travel agent which drew attention to the conditions of carriage in the tickets, but not, however, printed in the brochure itself. B booked a passage for P and himself on D’s vessel, and was subsequently given the tickets containing an exemption clause, which purported to exclude liability for personal injury. P was injured during the passage and sued for negligence.
D denied liability relying on the exemption clause in the tickets and the fact that B had been given the ship-owner’s brochure the contents of which referred to the conditions of carriage in the ticket.
The points of interest were that: (i) The court accepted that B acted as agent for P so knowledge of the content of the brochure which refers to the conditions of carriage in the ticket was attributed to P. (ii) The contract was concluded before the ticket was delivered, as a consequence, D could not rely on the exclusion clause. (iii) D could not rely on the fact that B had read the clause in the brochure and was therefore aware that there were exempting conditions.
In other words, website owners might need to make more effort to bring website terms and conditions updates to the attention of the party affected. The clause in use generally, which puts the onus on the affected party to be on the lookout for website updates, might be ineffective.