Earlier this week, several websites reported a 'glitch' on the website of US-based United Airlines. By 'tricking' the site using multiple web browser pages, users were able to fool the site into thinking they had accumulated enough frequent flyer miles to avail of free flights. Mashable, for example, reported that a journalist was able to secure flights from Newark Airport in New Jersey to Dublin, all for $49.40 (approximately €36) in taxes and charges. The writer in question didn't actually book any flights, but was easily able to access the final pages of the booking form. Other web users confirmed they had successfully reserved tickets.

A spokesman for the airline has said it won't honour any bookings made by customers who had deliberately tried to manipulate its website. Disgruntled customers have set up a petition to try and persuade the company to recognise the manipulated transactions.

This is not the first time that United Airlines has had to contend with a pricing error on their website. Only last month the company had to contend with another issue that allowed users to book free or extremely cheap flights. However, attributing the problem to 'human error', the website ultimately decided to honour the discounted rates:

We’ve reviewed the error that occurred yesterday and based on these specific circumstances, we will honor the tickets.

— United (@united) September 13, 2013