REGINA -- Using opposition research against the competition is a strategy as old as politics itself.

The rise of social media has added another tool for political parties.

"The boundaries between what’s public and what’s private are blurrier than they’ve ever been and they’ve changed rapidly," Jim Farney, a political science professor at the University of Regina, said.

"Because so much more of our lives are public, I think we do see the social media side played up."

This past weekend, Saskatchewan Party candidate Daryl Cooper in Saskatoon was replaced after making controversial posts on social media and Regina Rosemont candidate Alex Nau had to issue an apology over participating in a derogatory game about women in 2016.

On Monday, the Sask. Party attacked Regina Elphinstone-Centre NDP candidate Meara Conway over a Facebook post labelled as an attack on the province’s oil industry.

"This is getting to be a thing," Sask. Party Leader Scott Moe said. "We saw it in the federal election, we saw it in the last Saskatchewan election and we’re seeing it again."

NDP Leader Ryan Meili said whether a candidate’s social media posts should be used against them is something that needs further discussion.

"How much do we want to dig into people’s social media, certainly the further back you go, the more murky it gets," Meili said.

How someone conducts themselves online can be a window into who they are as a person, which Farney said is important in selecting who to vote for on election day.

"There is stuff that people say or do before they’re candidates that really does throw light on who they are and there is a public interest argument to be said for that," Farney said.

"What we’re really trying to assess is people’s judgement and character. Arguably some of these show poor judgment."

The way a party responds to controversial old social media posts from a candidate can also provide the public with information on what’s important to the party, according to Farney.

"What we can look to in these examples is not just the individual candidates, but also what does the party leadership feel is appropriate or inappropriate or forgivable," he said.

Farney added digging up old social media posts can be effective, but needs to be used responsibly.