Someone asked about petitions below with regards to the HDB. It's good to hear people want to write in and people are asking what's the best way of sending in a petition.
For the HDB for example, we had 3000 people sign physical letters in 3 weeks and were told that wasn't representative. What I would suggest is to actually send in emails individually if possible, or with small groups of friends, and that you include your full names and NRIC numbers in those emails.
I know that sometimes people do start petitions on websites with links to ask people to sign up. It's great that people feel strongly enough to do it, and to see how many people sign those petitions. It does show as an indicator how people feel about a situation.
The only thing is I don't think those petitions are taken very seriously by authorities. For one thing, most of them don't require full names and NRIC numbers so they're easy to dismiss in terms of credibility. I'm not even certain that for example that they are actually looked at by the authorities if someone does send them the URL, in any way more than a cursory glance.
What I think IS more effective is to write emails and snail mail. The reason I suggested writing individually or with small groups of friends is that people often feel slightly different about a certain situation - so it's good to have different voices speak up about it in their own words. Even if you do use someone else's letter, it does look like you did look through it and agree with it enough to put your full name and NRIC number on it.