On the front page there are 3 random holidays listed from the database....these show who is going away and where too but does not show the dates.
Anyone travelling to the same resort/hotel as you within the same date periods is shown to you and you to them.
One has to consider the implications of posting any info on the net and many members (As mentioned in part by Fiona earlier on in the topic) already post their dates in the threads which can be seen by anyone. So it's down to you as an individual whether you want to post publicly in a thread on here, as many do, post in the new meets database or do neither.
The security of your information is basically down to you as an individual. If you have disclosed your personal details to anyone either on the site or offline, then the onus is on you to determine whether you trust these people enough to post into the database. Many user do not think twice about posting in a thread saying they are going to xxxx hotel on yyyy date.
The choice, at the end of the day is down to you. The internet and HT provide plenty of anonymity with usernames and no-one is obliged to publish their true name and details on HT. If you have done so then the security is down to you.
Can I just reiterate that no-one can search for your holiday dates by username only by adding their own details can anyone see your holidays.
HTH
Van