Having internet access while on holidays can be handy for planning and leisure, but it also makes us more vulnerable to checking up on work at the same time. A survey suggests that many of us succumb to that temptation, with two-thirds saying they have taken advantage of technology to work during breaks.
The survey of 500 Australian workers, commissioned by HR advisory firm NorthgateArinso, also found that 30% of people worked during their daily commute. I do that myself, and I don't think that's problematic in and of itself; the issue is being sure your employer recognises that this is part of your work routine.
Similarly, the problem with working on holidays is partly a question of scale. There's a big difference between looking at your email once during a week-long vacation and dedicating time to it every day. The former ideally wouldn't happen, but shouldn't wreck the holiday for you or fellow travellers; the latter definitely suggests a problem.